i965: Fix a few base addresses on Broadwell.

i965: Fix a few base addresses on Broadwell.

We intended to set these 64-bit addresses to 0, and set the enable bit.
But, I accidentally placed the DWord with the high bits first, when it
should have been second.

This generally worked out, by luck - presumably General State Base
Address is initially zero, and ends up remaining that way in our
contexts since we bungled the "modify enable" bit.

v2: Fix MOCS shift on GSBA.  It should be 4, and I had 2.
    (Caught by Ben Widawsky.)

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>