FROMLIST: drm/bridge: dw_hdmi: support i2c extended read mode

FROMLIST: drm/bridge: dw_hdmi: support i2c extended read mode

"I2C Master Interface Extended Read Mode" implements a segment
pointer-based read operation using the Special Register configuration.

This patch fix https://patchwork.kernel.org/patch/7098101/ mentioned
"The current implementation does not support "I2C Master Interface
Extended Read Mode" to read data addressed by non-zero segment
pointer, this means that if EDID has more than 1 extension blocks"

With this patch,dw-hdmi can read EDID data with 1/2/4 blocks.

(am from https://patchwork.kernel.org/patch/9586343/)

BUG=chrome-os-partner:59768
TEST=fievel can read 1/2/4 blocks EDID data

Change-Id: I086e6ea63ec69c0532be445b958ce253a7f1f3cc
Signed-off-by: Nickey Yang <nickey.yang@rock-chips.com>
Reviewed-on: https://chromium-review.googlesource.com/442308
Reviewed-by: Douglas Anderson <dianders@chromium.org>