Need to adjust the pll up for deep color modes.
Additionally, the atom bpc defines were wrong in certain
cases.

v2: set the adjusted clock to the pll clock for hdmi deep
color.  This fixes display and audio issues with deep color
as reported by Andy Furniss <adf.lists@gmail.com>

v3: set crtc_clock as well

v4: setcrtcinfo on the adjusted mode

v5: just use the adjusted clock for setting the pll

v6: only use the adjusted clock for hdmi

v7: only DCE5 and DCE6 and bpc > 8
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>