intel/blorp: Update clear color state buffer during fast clears.

intel/blorp: Update clear color state buffer during fast clears.

We always want to update the fast clear color during a fast clear on
i965. On anv, we are doing that before a resolve, but by adding support
to blorp, we can do a similar thing and update it during a fast clear
instead.

The goal is to remove some code from anv that does such update, and
centralize everything in blorp, hopefully removing a lot of code
duplication. It also allows us to have a similar behavior on gen < 9 and
gen >= 10.

v5: s/we/we are/ (Jordan)

Signed-off-by: Rafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>