amdfwtool: Make NVRAM regions writeable

When ROM Armor is enabled and PSP is not in "capsule update mode",
the PSP can only write to PSP directory entries that have the writable
bit set. As the fTPM PSP trustlet must write to NVRAM regions as part
of the fTPM operation, set the writable bit on such regions.

Fixes crash on PSP side when using ROM Armor and fTPM.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Change-Id: I5668976d687e5f9aa3fc62e91adf6bde5cadb5b8
Reviewed-on: https://review.coreboot.org/c/coreboot/+/91699
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Maximilian Brune <maximilian.brune@9elements.com>

util/amdfwtool/amdfwtool.c

@@ -1127,6 +1127,7 @@ static void integrate_psp_firmwares(context *ctx,
 			pspdir->entries[count].rsvd = 0;
 			pspdir->entries[count].size = size;
 			pspdir->entries[count].addr = addr;
+			pspdir->entries[count].writable = 1;
 
 			pspdir->entries[count].address_mode =
 				SET_ADDR_MODE(pspdir, AMD_ADDR_REL_BIOS);