riscv: add missing header file includes

sparse identifies several missing prototypes caused by missing
preprocessor include directives:

arch/riscv/kernel/cpufeature.c:16:6: warning: symbol 'has_fpu' was not declared. Should it be static?
arch/riscv/kernel/process.c:26:6: warning: symbol 'arch_cpu_idle' was not declared. Should it be static?
arch/riscv/kernel/reset.c:15:6: warning: symbol 'pm_power_off' was not declared. Should it be static?
arch/riscv/kernel/syscall_table.c:15:6: warning: symbol 'sys_call_table' was not declared. Should it be static?
arch/riscv/kernel/traps.c:149:13: warning: symbol 'trap_init' was not declared. Should it be static?
arch/riscv/kernel/vdso.c:54:5: warning: symbol 'arch_setup_additional_pages' was not declared. Should it be static?
arch/riscv/kernel/smp.c:64:6: warning: symbol 'arch_match_cpu_phys_id' was not declared. Should it be static?
arch/riscv/kernel/module-sections.c:89:5: warning: symbol 'module_frob_arch_sections' was not declared. Should it be static?
arch/riscv/mm/context.c:42:6: warning: symbol 'switch_mm' was not declared. Should it be static?

Fix by including the appropriate header files in the appropriate
source files.

This patch should have no functional impact.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

arch/riscv/include/asm/irq.h

@@ -7,6 +7,9 @@
 #ifndef _ASM_RISCV_IRQ_H
 #define _ASM_RISCV_IRQ_H
 
+#include <linux/interrupt.h>
+#include <linux/linkage.h>
+
 #define NR_IRQS         0
 
 void riscv_timer_interrupt(void);

arch/riscv/include/asm/switch_to.h

@@ -6,6 +6,7 @@
 #ifndef _ASM_RISCV_SWITCH_TO_H
 #define _ASM_RISCV_SWITCH_TO_H
 
+#include <linux/sched/task_stack.h>
 #include <asm/processor.h>
 #include <asm/ptrace.h>
 #include <asm/csr.h>

arch/riscv/kernel/cpufeature.c

@@ -10,6 +10,7 @@
 #include <asm/processor.h>
 #include <asm/hwcap.h>
 #include <asm/smp.h>
+#include <asm/switch_to.h>
 
 unsigned long elf_hwcap __read_mostly;
 #ifdef CONFIG_FPU

arch/riscv/kernel/module-sections.c

@@ -8,6 +8,7 @@
 #include <linux/elf.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/moduleloader.h>
 
 unsigned long module_emit_got_entry(struct module *mod, unsigned long val)
 {

arch/riscv/kernel/process.c

@@ -7,6 +7,7 @@
  * Copyright (C) 2017 SiFive
  */
 
+#include <linux/cpu.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
@@ -19,6 +20,7 @@
 #include <asm/csr.h>
 #include <asm/string.h>
 #include <asm/switch_to.h>
+#include <asm/thread_info.h>
 
 extern asmlinkage void ret_from_fork(void);
 extern asmlinkage void ret_from_kernel_thread(void);

arch/riscv/kernel/reset.c

@@ -4,6 +4,7 @@
  */
 
 #include <linux/reboot.h>
+#include <linux/pm.h>
 #include <asm/sbi.h>
 
 static void default_power_off(void)

arch/riscv/kernel/smp.c

@@ -8,7 +8,9 @@
  * Copyright (C) 2017 SiFive
  */
 
+#include <linux/cpu.h>
 #include <linux/interrupt.h>
+#include <linux/profile.h>
 #include <linux/smp.h>
 #include <linux/sched.h>
 #include <linux/seq_file.h>

arch/riscv/kernel/smpboot.c

@@ -29,6 +29,7 @@
 #include <asm/tlbflush.h>
 #include <asm/sections.h>
 #include <asm/sbi.h>
+#include <asm/smp.h>
 
 #include "head.h"
 

arch/riscv/kernel/syscall_table.c

@@ -8,6 +8,7 @@
 #include <linux/syscalls.h>
 #include <asm-generic/syscalls.h>
 #include <asm/vdso.h>
+#include <asm/syscall.h>
 
 #undef __SYSCALL
 #define __SYSCALL(nr, call)	[nr] = (call),

arch/riscv/kernel/time.c

@@ -7,6 +7,7 @@
 #include <linux/clocksource.h>
 #include <linux/delay.h>
 #include <asm/sbi.h>
+#include <asm/processor.h>
 
 unsigned long riscv_timebase;
 EXPORT_SYMBOL_GPL(riscv_timebase);

arch/riscv/kernel/traps.c

@@ -3,6 +3,7 @@
  * Copyright (C) 2012 Regents of the University of California
  */
 
+#include <linux/cpu.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/sched.h>

arch/riscv/kernel/vdso.c

@@ -6,6 +6,7 @@
  * Copyright (C) 2015 Regents of the University of California
  */
 
+#include <linux/elf.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/binfmts.h>

arch/riscv/mm/context.c

@@ -7,6 +7,7 @@
 #include <linux/mm.h>
 #include <asm/tlbflush.h>
 #include <asm/cacheflush.h>
+#include <asm/mmu_context.h>
 
 /*
  * When necessary, performs a deferred icache flush for the given MM context,