efi: move fdt helper library

There is nothing ARM64 (or even ARM) specific about the efi fdt helper
library, which is used for locating or overriding a firmware-provided
devicetree in a UEFI system - so move it to loader/efi for reuse.

Move the fdtload.h include file to grub/efi and update path to
efi/fdtload.h in source code referring to it.

Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>

grub-core/Makefile.core.def

@@ -1707,7 +1707,7 @@ module = {
 
 module = {
   name = fdt;
-  arm64 = loader/arm64/fdt.c;
+  arm64 = loader/efi/fdt.c;
   common = lib/fdt.c;
   enable = fdt;
 };

grub-core/loader/arm64/linux.c

@@ -26,8 +26,8 @@
 #include <grub/mm.h>
 #include <grub/types.h>
 #include <grub/cpu/linux.h>
-#include <grub/cpu/fdtload.h>
 #include <grub/efi/efi.h>
+#include <grub/efi/fdtload.h>
 #include <grub/efi/pe32.h>
 #include <grub/i18n.h>
 #include <grub/lib/cmdline.h>

grub-core/loader/arm64/xen_boot.c

@@ -27,9 +27,9 @@
 #include <grub/misc.h>
 #include <grub/mm.h>
 #include <grub/types.h>
-#include <grub/cpu/fdtload.h>
 #include <grub/cpu/linux.h>
 #include <grub/efi/efi.h>
+#include <grub/efi/fdtload.h>
 #include <grub/efi/pe32.h>	/* required by struct xen_hypervisor_header */
 #include <grub/i18n.h>
 #include <grub/lib/cmdline.h>

grub-core/loader/efi/fdt.c

@@ -18,12 +18,12 @@
 
 #include <grub/fdt.h>
 #include <grub/mm.h>
-#include <grub/cpu/fdtload.h>
 #include <grub/err.h>
 #include <grub/dl.h>
 #include <grub/command.h>
 #include <grub/file.h>
 #include <grub/efi/efi.h>
+#include <grub/efi/fdtload.h>
 
 static void *loaded_fdt;
 static void *fdt;