i965: Advertise the CCS modifier

i965: Advertise the CCS modifier

v2: Rename modifier to be more smart (Jason)

FINISHME: Use the kernel's final choice for the fb modifier

bwidawsk@norris2:~/intel-gfx/kmscube (modifiers $) ~/scripts/measure_bandwidth.sh ./kmscube none
Read bandwidth: 603.91 MiB/s
Write bandwidth: 615.28 MiB/s
bwidawsk@norris2:~/intel-gfx/kmscube (modifiers $) ~/scripts/measure_bandwidth.sh ./kmscube ytile
Read bandwidth: 571.13 MiB/s
Write bandwidth: 555.51 MiB/s
bwidawsk@norris2:~/intel-gfx/kmscube (modifiers $) ~/scripts/measure_bandwidth.sh ./kmscube ccs
Read bandwidth: 259.34 MiB/s
Write bandwidth: 337.83 MiB/s

v2: Move all references to the new fourcc code(s) to this patch.
v3: Rebase, remove Yf_CCS (Daniel)

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Acked-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Chad Versace <chadversary@chromium.org>