arch/x86: Buildtest clang targets with VBOOT_STARTS_BEFORE_BOOTBLOCK

TESTED: google/vilboz boots with clang build.

Change-Id: Ie115c27b4cb0b8f83d7647bdd27ffcbac9376399
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69746
Reviewed-by: Martin L Roth <gaumless@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/x86/Kconfig

@@ -33,7 +33,7 @@ config ARCH_ALL_STAGES_X86_32
 	select ARCH_VERSTAGE_X86_32 if !VBOOT_STARTS_BEFORE_BOOTBLOCK
 	select ARCH_ROMSTAGE_X86_32
 	select ARCH_RAMSTAGE_X86_32
-	select ARCH_SUPPORTS_CLANG if !VBOOT_STARTS_BEFORE_BOOTBLOCK
+	select ARCH_SUPPORTS_CLANG
 
 # stage selectors for x64