soc/intel/elkhartlake: Increase BSP stack size by 1 KiB to 193 KiB

The Kconfig help section says FSP uses 192 KiB of stack (0x30000) and
coreboot's romstage requires ~1 KiB, but it is not satisfied currently.
Increase the BSP stack size by the missing 1KiB for romstage like
other SoCs do.

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Change-Id: Iddd4a4613bc174aec4331732371a27450225258c
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73820
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Mario Scheithauer <mario.scheithauer@siemens.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>

src/soc/intel/elkhartlake/Kconfig

@@ -85,7 +85,7 @@ config DCACHE_RAM_SIZE
 
 config DCACHE_BSP_STACK_SIZE
 	hex
-	default 0x30000
+	default 0x30400
 	help
 	  The amount of anticipated stack usage in CAR by bootblock and
 	  other stages. In the case of FSP_USES_CB_STACK default value will be