drm/kms: Parse the detailed time info in CEA-EDID

Sometimes we can obtain the EDID with multiple blocks from the display device.
For example: HDMI monitor.
When the CEA-EDID block is detected, we should also parse the detailed timing
info from it. Otherwise we will lose some modes for the display device.

The first step is check whether the CEA EDID block is found. If it exists,
it will skip the CEA-data block and parse the detailed timing info.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>