drm: allow passing possible_crtcs to drm_writeback_connector_init()

drm: allow passing possible_crtcs to drm_writeback_connector_init()

Clients of drm_writeback_connector_init() initialize the
possible_crtcs and then invoke the call to this API.

To simplify things, allow passing possible_crtcs as a parameter
to drm_writeback_connector_init() and make changes to the
other drm drivers to make them compatible with this change.

changes in v2:
	- split the changes according to their functionality

changes in v3:
	- allow passing possible_crtcs for existing users of
	  drm_writeback_connector_init()
	- squash the vendor changes into the same commit so
	  that each patch in the series can compile individually

changes in v4:
    - keep only changes related to possible_crtcs
	- add line breaks after ARRAY_SIZE
	- stop using temporary variables for possible_crtcs

changes in v5:
    - None

changes in v6:
    - None

changes in v7:
	- wrap long lines to match the coding style of existing drivers
	- Fix indentation and remove parenthesis where not needed
	- use u32 instead of uint32_t for possible_crtcs

Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Patchwork: https://patchwork.freedesktop.org/patch/483501/
Link: https://lore.kernel.org/r/1650984096-9964-2-git-send-email-quic_abhinavk@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>