anv: Emit the fast clear color address, instead of value.

anv: Emit the fast clear color address, instead of value.

On Gen10+, instead of copying the clear color from the state buffer to
the surface state, just use the address of the state buffer in the
surface state directly. This way we can avoid the copy from state buffer
to surface state.

v4:
 - Remove use_clear_address from anv code. (Jason)
 - Use the helper to extract clear color from attachment (Jason)

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>