drm/bridge: analogix_dp: move platform and PHY power handling into runtime PM

drm/bridge: analogix_dp: move platform and PHY power handling into runtime PM

Platform and PHY power isn't only required when the actual display data
stream is active, but may be required earlier to support AUX channel
transactions. Move them into the runtime PM calls, so they are properly
managed whenever various other parts of the driver need them to be active.

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/20240619182200.3752465-7-l.stach@pengutronix.de