i965: Fix HW blitter pitch limits

i965: Fix HW blitter pitch limits

The BLT pitch is specified in bytes for linear surfaces and in dwords
for tiled surfaces. In both cases the programmable limit is 32,767, so
adjust the check to compensate for the effect of tiling.

v2: Tweak whitespace for functions (Kenneth)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kristian Høgsberg <krh@bitplanet.net>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by Kenneth Graunke <kenneth@whitecape.org>
Cc: mesa-stable@lists.freedesktop.org