drm/vc4: hdmi: Restore cec physical address on reconnect

commit  63a434a7bce199474eb2600a9b3c5412ce4fab1c from
https://github.com/raspberrypi/linux.git

 rpi-5.10.y

Currently we call cec_phys_addr_invalidate on a hotplug deassert.
That may be due to a TV power cycling, or an AVR being switched
on (and switching edid).

This makes CEC unusable since our controller wouldn't have a physical
address anymore.

Set it back up again on the hotplug assert.

Fixes: 15b4511a ("drm/vc4: add HDMI CEC support")
Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Meng Li <Meng.Li@windriver.com>