i965/gen9: Enable rep clears on gen9

The (gen < 9) check in brw_clear() was too broad. It disabled all types
of fast color clears:
    a. singlesample rep clears
    b. singlesample MCS fast clears
    c. multisample MCS fast clears

The MCS clears are still buggy, but the rep clear works well. So let's
enable it.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2 files changed