drm/bridge: adv7511: Add Audio support

drm/bridge: adv7511: Add Audio support

This patch adds support to Audio for both adv7511 and adv7533
bridge chips.

This patch was originally from [1] by Lars-Peter Clausen <lars@metafoo.de>
and was adapted by Archit Taneja <architt@codeaurora.org> and
Srinivas Kandagatla <srinivas.kandagatla@linaro.org>.

Then I heavily reworked it to use the hdmi-codec driver. And also
folded in some audio packet initialization done by Andy Green
<andy.green@linaro.org>. So credit to them, but blame to me.

[1] https://github.com/analogdevicesinc/linux/blob/xcomm_zynq/drivers/gpu/drm/i2c/adv7511_audio.c

Cc: David Airlie <airlied@linux.ie>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Andy Green <andy@warmcat.com>
Cc: Dave Long <dave.long@linaro.org>
Cc: Guodong Xu <guodong.xu@linaro.org>
Cc: Zhangfei Gao <zhangfei.gao@linaro.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Jose Abreu <joabreu@synopsys.com>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: dri-devel@lists.freedesktop.org
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1480382552-28219-2-git-send-email-john.stultz@linaro.org