Thus this patch changes the EDID probing logic so that we
re-use the __adv7511_power_on/off() calls instead of duplciating
logic.

This does change behavior slightly as it adds the HPD signal
pulse to the EDID probe path, but Archit has had a patch to
add HPD signal pulse to the EDID probe path before, so this
should address the cases where that helped. Another difference
is that regcache_mark_dirty() is also called in the power off
path once EDID is probed.

Cc: David Airlie <airlied@linux.ie>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1484614372-15342-6-git-send-email-john.stultz@linaro.org