Implement GetDisplayCapabilities() to get a list of supported capabilities. It can also fix the segment fault while booting the Android on HWC2.3, caused by lack of this API.
Implement getDisplayIdentificationData() to get the EDID blob data along with the size and port. Add edid property in DrmConnector.
Signed-off-by: Lowry Li (Arm Technology China) lowry.li@arm.com