ASoC: ssm2518: Drop .volatile_reg implementation
ASoC: ssm2518: Drop .volatile_reg implementation

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 <b6ffd6973e972cb999e8e535ab74da7fee0c035f@ingics.com>
Acked-by: Lars-Peter Clausen <3318dc5ce3e4fb7c28a0b841b6801c884e1d0896@metafoo.de>
Signed-off-by: Mark Brown <b51b9a92386687a9ac927cebfa0f978adeb8cea5@kernel.org>

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