arch/x86/Kconfig: Deduplicate ARCH_SUPPORTS_CLANG selection

Change-Id: Iced69e0bce345748a43eb1c14bf17a683e26ba60
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/81020
Reviewed-by: Jérémy Compostella <jeremy.compostella@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>

src/arch/x86/Kconfig

@@ -5,6 +5,7 @@ config ARCH_X86
 	select PCI
 	select RELOCATABLE_MODULES
 	select HAVE_ASAN_IN_RAMSTAGE
+	select ARCH_SUPPORTS_CLANG
 
 if ARCH_X86
 
@@ -33,7 +34,6 @@ 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
 
 # stage selectors for x64
 
@@ -64,7 +64,6 @@ config ARCH_ALL_STAGES_X86_64
 	select ARCH_VERSTAGE_X86_64 if !VBOOT_STARTS_BEFORE_BOOTBLOCK
 	select ARCH_ROMSTAGE_X86_64
 	select ARCH_RAMSTAGE_X86_64
-	select ARCH_SUPPORTS_CLANG
 
 config HAVE_EXP_X86_64_SUPPORT
 	bool