drm/i915: enable 30bpp for DP outputs
drm/i915: enable 30bpp for DP outputs

We always limited the link bw calculations to 24bpp. Tested with
my shiny new high-bpc screen, seems to work as advertised.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=65280
Tested-by: shui yangwei <e88f955a2451fb640f2373e667605d06cec54572@intel.com>
Reviewed-by: Chris Wilson <711c73f64afdce07b7e38039a96d2224209e9a6c@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs