ARM: 7893/1: bitops: only emit .arch_extension mp if CONFIG_SMP
ARM: 7893/1: bitops: only emit .arch_extension mp if CONFIG_SMP

Uwe reported a build failure when targetting a NOMMU platform with my
recent prefetch changes:

  arch/arm/lib/changebit.S: Assembler messages:
  arch/arm/lib/changebit.S:15: Error: architectural extension `mp' is
			not allowed for the current base architecture

This is due to use of the .arch_extension mp directive immediately prior
to an ALT_SMP(...) instruction. Whilst the ALT_SMP macro will expand to
nothing if !CONFIG_SMP, gas will still choke on the directive.

This patch fixes the issue by only emitting the sequence (including the
directive) if CONFIG_SMP=y.

Tested-by: Uwe Kleine-König <181323dd666a182bc2d953e52d0ac3ab54cd8391@pengutronix.de>
Signed-off-by: Will Deacon <b913f13ef92ac157955c954ccaaff7be065faba4@arm.com>
Signed-off-by: Russell King <f6aa0246ff943bfa8602cdf60d40c481b38ed232@arm.linux.org.uk>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs