The implementation of ssm2518_register_volatile always returns false,
this behavior is the same as no .volatile_reg callback implementation
when cache_type != REGCACHE_NONE.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>