soc/intel/braswell: add default option to use public FSP

The current Braswell FSP 1.1 header in vendorcode/intel, for
which there is no publicly available FSP binary, contains silicon
init UPDs which are not found in the publicly available header/binary
in the FSP Github repo. This prevents new boards from being added
which use the public Braswell FSP header/binary.

To resolve this, move the UPDs not found in the public header from
the soc's chip.c to ramstage.c for the boards which use them. Add
a Kconfig option to use the current non-public FSP header and
select it for boards which need it (google/cyan variants); set the
public FSP option as the default. Use the Kconfig option to set
FSP_HEADER_PATH to ensure the correct header is used.

Test: build google/cyan and intel/strago using non-public and
public FSP header/binaries respectively.

Change-Id: I43cf18b98c844175a87b61fdbe4b0b24484e5702
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32381
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Frans Hendriks <fhendriks@eltan.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/src/mainboard/google/cyan/Kconfig b/src/mainboard/google/cyan/Kconfig
index b3c6790..aac14c0 100644
--- a/src/mainboard/google/cyan/Kconfig
+++ b/src/mainboard/google/cyan/Kconfig
@@ -16,6 +16,7 @@
 	select HAVE_ACPI_RESUME
 	select PCIEXP_L1_SUB_STATE if !BOARD_GOOGLE_CYAN
 	select SYSTEM_TYPE_LAPTOP
+	select USE_GOOGLE_FSP
 
 if BOARD_GOOGLE_BASEBOARD_CYAN