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
(cherry picked from commit 8da79b8378ae87474d8c47ad955e4833edf98359)