i965: Convert CC state on gen4-5 to genxml.

i965: Convert CC state on gen4-5 to genxml.

Use set_blend_entry_bits and set_depth_stencil_bits to fill most of the
color calc struct, and then manually update the rest.

v2:
   - Always check for depth_irb (Ken)
   - Always set Backface Stencil Ref (Ken)
   - Always set alpha reference value (Ken)

Signed-off-by: Rafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>