CHROMIUM: ALSA: ASoC: exynos hdmi - fix audio transfer on unplug

CHROMIUM: ALSA: ASoC: exynos hdmi - fix audio transfer on unplug

Because hotplug handling timeout was increased,
it is no longer safe to read HDMI_MODE_SEL in hdmi_audio_hotplug_func,
since HDMI might be off at that time.

This broke transferring audio to internal speakers on HDMI unplug,
since bogus value was read.

So, move the code that handles DVI plugging inside "if (plugged)",
where reading HDMI registers is safe, since it is powered on.

BUG=chromium:222145,chromium:239641
TEST=Various HDMI/DVI plug/unplug scenarios, the most complex being:
play music, plug HDMI, suspend, unplug HDMI, plug DVI, resume,
listen to sound on internal speakers.

Signed-off-by: Yuly Novikov <ynovikov@chromium.org>
Change-Id: I9d27d0e388f444756576e643e20811901c6afe85
Reviewed-on: https://gerrit.chromium.org/gerrit/51178
Reviewed-by: Dylan Reid <dgreid@chromium.org>