So that we can export symbols directly from assembly files, let's make
use of the generic <asm/export.h>. We have a few symbols that we'll want
to conditionally export for !KASAN kernel builds, so we add a helper for
that in <asm/assembler.h>.
Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>