drm/msm/dpu: Move LM CRC code into separate method

Move layer mixer-specific section of dpu_crtc_get_crc() into a separate
helper method. This way, we can make it easier to get CRCs from other HW
blocks by adding other get_crc helper methods.

Changes since V1:
- Move common bitmasks to dpu_hw_util.h
- Move common CRC methods to dpu_hw_util.c
- Update copyrights
- Change crcs array to a dynamically allocated array and added it as a
  member of crtc_state

Changes since V2:
- Put changes for hw_util into a separate commit
- Revert crcs array to a static array
- Add else case for set_crc_source to return EINVAL if no valid source
  is selected
- Add DPU_CRTC_MAX_CRC_ENTRIES macro

Changes since V3:
- Move crcs array into dpu_crtc_get_lm_crc
- Remove comment about crcs array in dpu_crtc_state struct
- Revert `lm` rename
- Remove DPU_CRTC_MAX_CRC_ENTRIES macro
- Return EINVAL in dpu_crtc_get_crc if no valid CRC source is set

Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/490735/
Link: https://lore.kernel.org/r/20220622171835.7558-2-quic_jesszhan@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>