Move layer mixer specific MISR methods to generalized helper methods.
This will make it easier to add CRC support for other blocks in the
future.

Changes since V2:
- Reordered parameters so that offsets are after hw_blk_reg_map
- Fixed mismatched whitespace in bitmask definitions
Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/490732/
Link: https://lore.kernel.org/r/20220622171835.7558-3-quic_jesszhan@quicinc.comSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>