EDID/DP fixes for proper bpc detection of displays.

[Mario Kleiner]

Updated series to fix the regressions introduced into stable
kernels for active Displayport to dual-link DVI converters and
for active Displayport to VGA converters. Also to fix this stuff
better for Linux 4.8.

Patch 1 + 2 are needed to fix the regressions in the stable
kernels. These are meant for easy backporting to all affected
kernels.

Patch 3: A DP helper for parsing sink bpc from DP aux data to
assist drivers if they can't get bpc from EDID.

Patch 4: Make intel kms use patch 3.

Patch 5: Make the EDID parser recognize the "DFP1.x compatible TMDS"
bit by which DVI sinks can declare they support at least 8 bpc according
to DFP spec. This one if applied would let me sleep so much better, as
the common special display equipment for neuroscience research, which is
all DVI based atm., sets that bit in its EDID 1.3.

Thanks,
-mario