The defines for the registers were brought over from i915 while
bootstrapping the driver. As xe supports TGL and later only, it doesn't
make sense to keep the GEN* prefixes and suffixes in the registers: TGL
is graphics version 12, previously called "GEN12". So drop the prefix
everywhere.

v2:
  - Also drop _TGL suffix and reword commit message as suggested
    by Matt Roper. While at it, rename VSUNIT_CLKGATE_DIS_TGL to
    VSUNIT_CLKGATE2_DIS with the additional "2", so it doesn't clash
    with the define for the other register
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://lore.kernel.org/r/20230427223256.1432787-3-lucas.demarchi@intel.comSigned-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>