loongarch: Add auxiliary files

Add support for manipulating architectural cache and timers, and EFI
memory maps.

Signed-off-by: Zhou Yang <zhouyang@loongson.cn>
Signed-off-by: Xiaotian Wu <wuxiaotian@loongson.cn>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

grub-core/lib/efi/halt.c

@@ -31,7 +31,7 @@ grub_halt (void)
   grub_machine_fini (GRUB_LOADER_FLAG_NORETURN |
 		     GRUB_LOADER_FLAG_EFI_KEEP_ALLOCATED_MEMORY);
 #if !defined(__ia64__) && !defined(__arm__) && !defined(__aarch64__) && \
-    !defined(__riscv)
+    !defined(__loongarch__) && !defined(__riscv)
   grub_acpi_halt ();
 #endif
   efi_call_4 (grub_efi_system_table->runtime_services->reset_system,