amd/common: cleanup DATA_FORMAT/NUM_FORMAT field names

amd/common: cleanup DATA_FORMAT/NUM_FORMAT field names

The field layout wasn't actually changed in gfx9, so having the suffix
isn't very useful. The field *contents* were changed, but this is
reflected in the V_xxx_xxx definitions and is taken into account by
the ac_debug logic based on the register JSON.

This aligns the definitions with what will be generated from the
register JSON.