anv: enable FCV for Gen12.5

anv: enable FCV for Gen12.5

Now that we have proper handling of FCV_CCS_E everywhere, we can turn
this on for Gen12.5.

This helps fix a performance regression where enabling fast
clears to non-zero values with CCS_E caused additional partial resolves,
regressing performance on certain games. Performance is helped on the
following games:
  - F1'22: +45%
  - RDR2: +6%

Signed-off-by: Rohan Garg <rohan.garg@intel.com>
Reviewed-by: Nanley Chery <nanley.g.chery@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25589>