Enable cache on ARM U-Boot port.

Without it the port is reidiculously slow.

include/grub/arm/system.h

@@ -1,13 +1,18 @@
 #ifndef GRUB_SYSTEM_CPU_HEADER
 #define GRUB_SYSTEM_CPU_HEADER
 
+#include <grub/types.h>
+
 enum
   {
     GRUB_ARM_MACHINE_TYPE_RASPBERRY_PI = 3138,
     GRUB_ARM_MACHINE_TYPE_FDT = 0xFFFFFFFF
   };
 
-void grub_arm_disable_caches_mmu (void);
+void EXPORT_FUNC(grub_arm_disable_caches_mmu) (void);
+void grub_arm_enable_caches_mmu (void);
+void grub_arm_enable_mmu (grub_uint32_t *mmu_tables);
+void grub_arm_clear_mmu_v6 (void);
 
 #endif /* ! GRUB_SYSTEM_CPU_HEADER */
 

include/grub/cache.h

@@ -45,4 +45,9 @@ grub_arch_sync_dma_caches (void *address __attribute__ ((unused)),
 #endif
 #endif
 
+#ifdef __arm__
+void
+grub_arm_cache_enable (void);
+#endif
+
 #endif /* ! GRUB_CACHE_HEADER */