Give the "DFP 1.x" bit a proper name, and clean up the rest
of the bits defines as well.

Cc: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190529110204.2384-1-ville.syrjala@linux.intel.comReviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Mario Kleiner <mario.kleiner.de@gmail.com>