arch/x86: Remove NO_FIXED_XIP_ROM_SIZE

The variable SETUP_XIP_CACHE provides us a working
alternative.

Change-Id: I6e3befedbbc7967b71409640dc81a0c2a9b3e511
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41821
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/cpu/amd/agesa/Kconfig

@@ -16,7 +16,6 @@ config CPU_AMD_AGESA
 	select LAPIC_MONOTONIC_TIMER
 	select SPI_FLASH if HAVE_ACPI_RESUME
 	select SMM_ASEG
-	select NO_FIXED_XIP_ROM_SIZE
 	select SSE2
 
 if CPU_AMD_AGESA

src/cpu/amd/pi/Kconfig

@@ -16,7 +16,6 @@ config CPU_AMD_PI
 	select LAPIC_MONOTONIC_TIMER
 	select SPI_FLASH if HAVE_ACPI_RESUME
 	select SMM_ASEG
-	select NO_FIXED_XIP_ROM_SIZE
 	select SSE2
 
 if CPU_AMD_PI