drm/bridge: analogix_dp: Add support for phy configuration.

drm/bridge: analogix_dp: Add support for phy configuration.

Add support to configurate link rate, lane count, voltage swing and
pre-emphasis with phy_configure(). It is helpful in application scenarios
where analogix controller is mixed with the phy of other vendors.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
Link: https://lore.kernel.org/r/20250310104114.2608063-4-damon.ding@rock-chips.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>