i965/gen7: Add CC viewport setup to blorp code.

i965/gen7: Add CC viewport setup to blorp code.

When doing fast clears, a fulsim warning said that the batch was being
emitted without the viewport set up.  While the fast clear pass I was
looking at doesn't use the clear value, the later resolves which also
didn't set up the vieport would trigger the same.  It's not obvious
from the error message whether it meant "fast clear value gets clamped
to something you haven't defined" or "fast clear value doesn't get
clamped, and I saw it was out of the current (uninitialized) range,
and you probably wanted it clamped to that (uninitialized) range".  Be
paranoid and assume the first case.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>