x86/asm: Provide a Kconfig symbol for disabling old assembly annotations

As x86 was converted to use the modern SYM_ annotations for assembly,
ifdefs were added to remove the generic definitions of the old style
annotations on x86. Rather than collect a list of architectures in the
ifdefs as more architectures are converted over, provide a Kconfig
symbol for this and update x86 to use it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lkml.kernel.org/r/20200416182402.6206-1-broonie@kernel.org