[Intel-gfx] [PATCH 0/3] [DRM/I915] use the sdvo device info parsed from VBT to initialize SDVO device

[yakui_zhao]

Hi, 
        The following is the patch set that use the SDVO device info
parsed from general definition block to initialize the SDVO device.
        It is to fix the following bug: 
        http://bugs.freedesktop.org/show_bug.cgi?id=20429

        By parsing the general definition block of VBT we can get the
relationship between the DVO port and slave address. For example: the
SDVO wiring, the SDVO slave address. And then we use the info to
initialize the SDVO device. If the slave address can obtained for SDVO
port(SDVOB/SDVOC), it will be initialized correctly. If no slave address
is found in the SDVO device info parsed from VBT, it will return the slave address 
by using the following flowchart:
        a. If the SDVO device info is found for another SDVO port, it will
return the slave address that is not used. For example: if 0x70 is used, then
0x72 is returned. If 0x72 is used, 0x70 is returned.
        b. If no SDVO device info is found for another SDVO port, it will
return 0x70 for SDVOB and 0x72 for SDVOC.
        
	Patch 01/3: Add the definition of child_device_config.
        Patch 02/3: parse general definition block to get the SDVO
device info.
        Patch 03/3: Initialize the SDVO device based on the the sdvo
device info parsed from general definition block

Welcome the comments.

Yakui