efi: rt-wrapper: Add missing include

Add the missing #include of asm/assembler.h, which is where the ldr_l
macro is defined.

Fixes: ff7a1679 ("arm64: efi: Execute runtime services from a dedicated stack")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

arch/arm64/kernel/efi-rt-wrapper.S

@@ -4,6 +4,7 @@
  */
 
 #include <linux/linkage.h>
+#include <asm/assembler.h>
 
 SYM_FUNC_START(__efi_rt_asm_wrapper)
 	stp	x29, x30, [sp, #-112]!