util/cbfstool: Add support for ARM64 UefiPayload

UEFI payload is supported on some ARM64 platforms, for example MT8195.
As a result, add MACHINE_TYPE_ARM64 to support ARM SystemReady.

Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Change-Id: I4c0c6e263bd2f518a62ff9db44d72dd31086756a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58055
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>

util/cbfstool/coff.h

@@ -25,6 +25,7 @@ typedef struct {
 
 #define MACHINE_TYPE_X86 0x014c
 #define MACHINE_TYPE_X64 0x8664
+#define MACHINE_TYPE_ARM64 0xAA64
 typedef struct {
 	uint8_t  signature[4];
 	uint16_t machine;