i915: fix i915_texture_layout_2d() calculation
What does this MR do and why?
i915: fix i915_texture_layout_2d() calculation
Indeed, nblocksy was calculated with width instead of height. This was
an issue on non-square textures. This change fixes around 16 piglit gpu
tests on my configuration.
Fixes: b1ed72ebe259 ("Move the remaining format pf_get_* functions to u_format.h.")
Signed-off-by: Patrick Lerda <patrick9876@free.fr>