regcache: Introduce the index parsing API by stride order

Here introduces regcache_get_index_by_order() for regmap cache,
which uses the register stride order and bit rotation, to improve
the performance.

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
1 file changed