Guo Zeng authored Sep 17, 2015 and Mark Brown committed Sep 17, 2015

Some chips have separate unmask registers from mask registers for
some consideration of concurrency SMP write performance. And this
patch adds a flag for it.

An user will be CSR SiRFSoC ARM chips.

Signed-off-by: Guo Zeng <Guo.Zeng@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@kernel.org>