drm/bridge: analogix_dp: handle clock via runtime PM

There is no reason to enable the controller clock in driver probe, as
there is no HW initialization done in this function. Instead rely on
either runtime PM to handle the controller clock or statically enable
it in the driver bind routine, after which real hardware access is
required to work.

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/20240619182200.3752465-4-l.stach@pengutronix.de