i965: Add Gen9 surface state decoding

i965: Add Gen9 surface state decoding

Gen9 surface state is very similar to the previous generation. The important
changes here are aux mode, and the way clear colors work.

NOTE: There are some things intentionally left out of this decoding.

v2: Redo the string for the aux buffer type to address compressed variants.

v3: Use the shift for compression enable (instead of compression mode) (Topi)

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>