Add missing cache.c

grub-core/Makefile.core.def

@@ -158,6 +158,7 @@ kernel = {
   emu = kern/emu/misc.c;
   emu = kern/emu/mm.c;
   emu = kern/emu/time.c;
+  emu = kern/emu/cache.c;
 
   videoinkernel = lib/arg.c;
   videoinkernel = term/gfxterm.c;

grub-core/kern/emu/cache.c

@@ -0,0 +1,10 @@
+
+#include <grub/cache.h>
+
+void __clear_cache (char *beg, char *end);
+
+void
+grub_arch_sync_caches (void *address, grub_size_t len)
+{
+  __clear_cache (address, (char *) address + len);
+}