drm/i2c: adv7511: Add drm_bridge/connector for ADV7533

Create bridge and connector helper functions. These internally refer to
the ADV75xx helper functions.

The driver registers a drm_bridge object during probe. The bridge, in
turn registers a HDMI connector when a user attaches the bridge.

Therefore, when the device type is ADV7533, we create bridge and
connector entities, and when it's ADV7511, we create a slave encoder as
before.

Since the i2c driver is still wrapped around by the drm_i2c_slave_encoder
struct. We make sure the encoder_init op returns an error when the device
type is ADV7533.

Signed-off-by: Archit Taneja <architt@codeaurora.org>