drm/bridge: analogix_dp: move basic controller init into runtime PM

Make sure the controller is in a basic working state after runtime
resume. Keep the analog function enable in the mode set path as this
enables parts of the PHY that are only required to be powered when
there is a data stream being sent out.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240619182200.3752465-8-l.stach@pengutronix.de