mfd: wcd9xxx: Add support for REPEAT_CHANGE_VALUE

Slimbus supports ability to write upto 16 bytes to the same register as
one transaction on the bus through REPEAT_CHANGE_VALUE slimbus message.
Add support to write codec register with multiple values using
REPEAT_CHANGE_VALUE. Not all sizes from 1 to 16 are supported by such a
message, add support in driver to be able to write all sizes from 1 to
16 by splitting the register writes of unsupported sizes into multiple
writes of supported sizes.

Change-Id: I33fdd983068bc10f65523b2a95f1d7741fa6c486
Signed-off-by: Bhalchandra Gajare <gajare@codeaurora.org>