lib/Kconfig.debug: Add ARCH_HAS_DEBUG_VIRTUAL

DEBUG_VIRTUAL currently depends on DEBUG_KERNEL && X86. arm64 is getting
the same support. Rather than add a list of architectures, switch this
to ARCH_HAS_DEBUG_VIRTUAL and let architectures select it as
appropriate.
Acked-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/x86/Kconfig

@@ -46,6 +46,7 @@ config X86
 	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_DISCARD_MEMBLOCK
 	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
+	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FAST_MULTIPLIER

lib/Kconfig.debug

@@ -622,9 +622,12 @@ config DEBUG_VM_PGFLAGS
 
 	  If unsure, say N.
 
+config ARCH_HAS_DEBUG_VIRTUAL
+	bool
+
 config DEBUG_VIRTUAL
 	bool "Debug VM translations"
-	depends on DEBUG_KERNEL && X86
+	depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
 	help
 	  Enable some costly sanity checks in virtual to page code. This can
 	  catch mistakes with virt_to_page() and friends.