soc/intel: indicate to build system that XIP_ROM_SIZE isn't used

The XIP_ROM_SIZE Kconfig variable isn't used for these chipsets.
Therefore, indicate as such so that romstage can be placed in
cbfs less rigidly.

Change-Id: If5cae10b90e05029df56c282e8adf37fa0102955
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/14626
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>
diff --git a/src/soc/intel/baytrail/Kconfig b/src/soc/intel/baytrail/Kconfig
index fcf382e..df8765d 100644
--- a/src/soc/intel/baytrail/Kconfig
+++ b/src/soc/intel/baytrail/Kconfig
@@ -18,6 +18,7 @@
 	select HAVE_HARD_RESET
 	select MMCONF_SUPPORT
 	select MMCONF_SUPPORT_DEFAULT
+	select NO_FIXED_XIP_ROM_SIZE
 	select RELOCATABLE_MODULES
 	select RELOCATABLE_RAMSTAGE
 	select PARALLEL_MP