drm/msm/dp: fix all kernel-doc warnings

drm/msm/dp: fix all kernel-doc warnings

Correct and add kernel-doc comments to eliminate all warnings:

Warning: ../drivers/gpu/drm/msm/dp/dp_debug.h:31 expecting prototype for
 msm_dp_debug_get(). Prototype was for msm_dp_debug_init() instead
Warning: ../drivers/gpu/drm/msm/dp/dp_drm.c:24 function parameter
 'connector' not described in 'msm_dp_bridge_detect'
Warning: ../drivers/gpu/drm/msm/dp/dp_link.h:90 expecting prototype for
 mdss_dp_test_bit_depth_to_bpp(). Prototype was for
 msm_dp_link_bit_depth_to_bpp() instead
Warning: ../drivers/gpu/drm/msm/dp/dp_link.h:126 function parameter
 'aux' not described in 'msm_dp_link_get'
Warning: ../drivers/gpu/drm/msm/dp/dp_link.h:126 function parameter
 'dev' not described in 'msm_dp_link_get'
Warning: ../drivers/gpu/drm/msm/dp/dp_panel.h:70 function parameter
 'bw_code' not described in 'is_link_rate_valid'
Warning: ../drivers/gpu/drm/msm/dp/dp_panel.h:84 expecting prototype for
 msm_dp_link_is_lane_count_valid(). Prototype was for
 is_lane_count_valid() instead

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/695647/
Link: https://lore.kernel.org/r/20251219184638.1813181-3-rdunlap@infradead.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>