ASoC: hdmi-codec: Get ELD in before reporting plugged event

In plugged callback, ELD should be updated from display driver so that
user space can query information from ELD immediately after receiving jack
plugged event.

When jack is unplugged, clear ELD buffer so that user space does not get
obsolete information of unplugged HDMI.

Signed-off-by: Cheng-Yi Chiang <cychiang@chromium.org>
Link: https://lore.kernel.org/r/20201118043852.1338877-1-cychiang@chromium.org


Signed-off-by: Mark Brown <broonie@kernel.org>