powerpc: Move ptrace into a subdirectory.

In order to allow splitting of ptrace depending on the different
CONFIG_ options, create a subdirectory dedicated to ptrace and move
ptrace.c and ptrace32.c into it.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9ebcbe37834e9d447dd97f4381084795a673260c.1582848567.git.christophe.leroy@c-s.fr

arch/powerpc/kernel/Makefile

@@ -3,8 +3,6 @@
 # Makefile for the linux kernel.
 #
 
-CFLAGS_ptrace.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
-
 ifdef CONFIG_PPC64
 CFLAGS_prom_init.o	+= $(NO_MINIMAL_TOC)
 endif
@@ -41,15 +39,15 @@ CFLAGS_cputable.o += -DDISABLE_BRANCH_PROFILING
 CFLAGS_btext.o += -DDISABLE_BRANCH_PROFILING
 endif
 
-obj-y				:= cputable.o ptrace.o syscalls.o \
+obj-y				:= cputable.o syscalls.o \
 				   irq.o align.o signal_32.o pmc.o vdso.o \
 				   process.o systbl.o idle.o \
 				   signal.o sysfs.o cacheinfo.o time.o \
 				   prom.o traps.o setup-common.o \
 				   udbg.o misc.o io.o misc_$(BITS).o \
 				   of_platform.o prom_parse.o
-obj-$(CONFIG_PPC64)		+= setup_64.o sys_ppc32.o \
-				   signal_64.o ptrace32.o \
+obj-y				+= ptrace/
+obj-$(CONFIG_PPC64)		+= setup_64.o sys_ppc32.o signal_64.o \
 				   paca.o nvram_64.o firmware.o note.o \
 				   syscall_64.o
 obj-$(CONFIG_VDSO32)		+= vdso32/

arch/powerpc/kernel/ptrace/Makefile

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel.
+#
+
+CFLAGS_ptrace.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
+
+obj-y				+= ptrace.o
+obj-$(CONFIG_PPC64)		+= ptrace32.o