i965: Rework SURFACE_STATE entries for Broadwell.

i965: Rework SURFACE_STATE entries for Broadwell.

v2: Add missing SCS setting in gen8_emit_buffer_surface_state (caught by
    Eric Anholt).

v3: Use stored QPitch rather than recomputing it.

v4: Shift QPitch by 2 when setting it in the packet; bits 14:0 store
    bits 16:2 of the actual value (fixes myriads of cube and array
    texturing tests).  Also, only enable cube face bits for cubemaps
    (matches Chris Forbes' commit on master).  Port to use offset64.

v5: s/gl_format/mesa_format/g

v6: Fix DW5 of renderbuffer state, which neglected to subtract
    irb->mt->first_level.  Use vertical_alignment() rather than
    hardcoding 4.  Use ffs for multisample counts rather than a
    large switch statement (all caught/suggested by Eric).

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>