atlas: Check DP MF-bit against selected pin cfg
atlas: Check DP MF-bit against selected pin cfg

When we are configuring a Type-C port for DisplayPort alternate mode, we
should check to see that the selected pin config supports multi-function
mode or not.  This commit fixes a bug where we were setting the
SuperSpeed muxes based solely upon the Multi-function Preferred bit in
the DPStatus VDO.  Some Type-C video adapters are buggy and set the MF
preferred bit without actually supporting an MF pin configuration.
Therefore, we trust the reported supported pin configurations in the
DiscMode VDO.

BRANCH=master
BUG=chromium:919756,b:138874110

TEST=Enable DRM debug by "echo 0xe > /sys/module/drm/parameters/debug"
Monitor dmesg.
Look for output indicating "Link training successful at 5400000 4 lanes".
Look for monitor output at UHD4k60 on Acer B326HK using OSD.

Change-Id: I946e601ed672031bc4606878531c561cf487a914
Signed-off-by: Matthew Blecker <d18f4466f2802f9c78c5c14a42b8c21fdbfabfcd@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1737273
Reviewed-by: Nitin Kolluru <bc2d92dd98caa1d939292891a48c5ccc55a8a8d0@google.com>
Reviewed-by: Caveh Jalali <08e24a66aefda7a55ca7d73f8903e0fb16eec763@google.com>
Tested-by: Nitin Kolluru <bc2d92dd98caa1d939292891a48c5ccc55a8a8d0@google.com>
Commit-Queue: Caveh Jalali <08e24a66aefda7a55ca7d73f8903e0fb16eec763@google.com>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec