drm/msm/dp: use the eDP bridge ops to validate eDP modes

drm/msm/dp: use the eDP bridge ops to validate eDP modes

The eDP and DP interfaces shared the bridge operations and
the eDP specific changes were implemented under is_edp check.
To add psr support for eDP, we started using a new set of eDP
bridge ops. We are moving the eDP specific code in the
dp_bridge_mode_valid function to a new eDP function,
edp_bridge_mode_valid under the eDP bridge ops.

Signed-off-by: Sankeerth Billakanti <quic_sbillaka@quicinc.com>
Signed-off-by: Vinod Polimera <quic_vpolimer@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/524736/
Link: https://lore.kernel.org/r/1677774797-31063-11-git-send-email-quic_vpolimer@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>