linux-phytec-ti

drm/bridge: cdns-mhdp: Probe and add the bridge even without firmware

Load the firmware asynchronously and probe and add the bridge even we
do not yet have it. This makes it possible to pull up the DRM device
and get the other displays working even if we still have to wait for
display port firmware. The display port is locked in disconnected
state until the firmware is loaded and the DP IP is properly enabled.

The patch adds one lock to protect hw_state and bridge_attached in
the driver data struct from from a race between the DRM operations and
the asynchronous FW loading.

Signed-off-by: Jyri Sarha <jsarha@ti.com>