cpu/x86: Make 1GB paging the default

This patch flips the polarity of CONFIG_USE_1G_PAGES_TLB into
CONFIG_NEED_SMALL_2MB_PAGE_TABLES which is off by default, meaning
CPUs added in the future will automatically build the smaller 1GB pages.
We can expect support for this feature to be available on all future CPU
generations (with the possible exception of embedded edge cases), so
this default setting should make mistakes less likely and keep
maintenance effort lower. (Besides, enabling the support where it
doesn't work fails fast, whereas keeping it disabled where it could work
is an inefficiency that can easily go overlooked for a long time.)

While this is technically a CPU feature, not a northbridge feature, we
support a lot more individual CPUs than northbridges in the pre-SoC era,
and they tend to be closely coupled anyway. So select the option at the
northbridge level for older CPUs to keep things simpler.

Change-Id: I2cf1237a7fb63b8904c2a3d57fead162c66bacde
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82792
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/src/soc/intel/elkhartlake/Kconfig b/src/soc/intel/elkhartlake/Kconfig
index cb080f4..9bee9be 100644
--- a/src/soc/intel/elkhartlake/Kconfig
+++ b/src/soc/intel/elkhartlake/Kconfig
@@ -24,6 +24,7 @@
 	select INTEL_GMA_ADD_VBT if RUN_FSP_GOP
 	select MP_SERVICES_PPI_V1
 	select MRC_SETTINGS_PROTECT
+	select NEED_SMALL_2MB_PAGE_TABLES
 	select PARALLEL_MP_AP_WORK
 	select PLATFORM_USES_FSP2_1
 	select PMC_GLOBAL_RESET_ENABLE_LOCK