drm/vc4: hdmi: Fix HPD GPIO detection

drm/vc4: hdmi: Fix HPD GPIO detection

[ Upstream commit e32e5723256a99c5324824503572f743377dd0fe ]

Prior to commit 6800234ceee0 ("drm/vc4: hdmi: Convert to gpiod"), in the
detect hook, if we had an HPD GPIO we would only rely on it and return
whatever state it was in.

However, that commit changed that by mistake to only consider the case
where we have a GPIO and it returns a logical high, and would fall back
to the other methods otherwise.

Since we can read the EDIDs when the HPD signal is low on some displays,
we changed the detection status from disconnected to connected, and we
would ignore an HPD pulse.

Fixes: 6800234ceee0 ("drm/vc4: hdmi: Convert to gpiod")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20211025152903.1088803-3-maxime@cerno.tech
Signed-off-by: Sasha Levin <sashal@kernel.org>