soc/intel/icelake: Allow coreboot to reserve stack for fsp

Change-Id: I5f2d9548b8e2c7b1d154b7bad126ec7b1052231a
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Signed-off-by: Aamir Bohra <aamir.bohra@intel.com>
Reviewed-on: https://review.coreboot.org/29317
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Shelley Chen <shchen@google.com>
diff --git a/src/soc/intel/icelake/Kconfig b/src/soc/intel/icelake/Kconfig
index 664add2..c4ee841 100644
--- a/src/soc/intel/icelake/Kconfig
+++ b/src/soc/intel/icelake/Kconfig
@@ -19,6 +19,7 @@
 	select CACHE_RELOCATED_RAMSTAGE_OUTSIDE_CBMEM
 	select COMMON_FADT
 	select CPU_INTEL_FIRMWARE_INTERFACE_TABLE
+	select FSP_USES_CB_STACK
 	select GENERIC_GPIO_LIB
 	select HAVE_FSP_GOP
 	select INTEL_DESCRIPTOR_MODE_CAPABLE
@@ -89,6 +90,7 @@
 
 config DCACHE_BSP_STACK_SIZE
 	hex
+	default 0x20000 if FSP_USES_CB_STACK
 	default 0x4000
 	help
 	  The amount of anticipated stack usage in CAR by bootblock and