amdfwtool: Set the region_type as 0 for entry "BIOS level 2"

This region_type is actually not used. But we need to set it
explicitly as a known value.

We can refer "PSP spec #55758" or the link below:
   https://doc.coreboot.org/soc/amd/psp_integration.html

Change-Id: I8b914f9f02beecce707aba86248826cd9208e6c0
Signed-off-by: Zheng Bao <fishbaozi@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/54871
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>

util/amdfwtool/amdfwtool.c

@@ -1044,6 +1044,7 @@ static void integrate_bios_firmwares(context *ctx,
 
 	if (biosdir2) {
 		biosdir->entries[count].type = AMD_BIOS_L2_PTR;
+		biosdir->entries[count].region_type = 0;
 		biosdir->entries[count].size =
 					+ MAX_BIOS_ENTRIES
 					* sizeof(bios_directory_entry);