soc/intel/apl: Use Kconfig to enable CseRbp

This patch makes SKIP_CSE_RBP=y default for Apollo Lake if Boot Device is
memory mapped and ensures SkipCseRbp UPD is guarded against this config.

Signed-off-by: Sean Rhodes <sean@starlabs.systems>
Change-Id: Ifd01a25443e2582a90529e55be8d34a88342a103
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61282
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/soc/intel/apollolake/Kconfig b/src/soc/intel/apollolake/Kconfig
index 38e7491..f9ad4d6 100644
--- a/src/soc/intel/apollolake/Kconfig
+++ b/src/soc/intel/apollolake/Kconfig
@@ -117,6 +117,15 @@
 	# provide a custom media driver that facilitates mapping
 	select X86_CUSTOM_BOOTMEDIA
 
+config SKIP_CSE_RBP
+	bool
+	default y if BOOT_DEVICE_MEMORY_MAPPED
+	help
+	  Tell CSE we do not need to use Ring Buffer Protocol (RBP) to fetch
+	  firmware for us if we are using memory-mapped SPI. This lets CSE
+	  state machine transition to next boot state, so that it can function
+	  as designed.
+
 config DISABLE_HECI1_AT_PRE_BOOT
 	default y