i965: Move the rest of intel_tex_layout.c into brw_tex_layout.c.

i965: Move the rest of intel_tex_layout.c into brw_tex_layout.c.

The texture alignment unit functions are called from brw_tex_layout.c,
so it makes sense to put them there.  Since the only caller of
intel_get_texture_alignment_unit() is in brw_tex_layout.c, it could be
made into a static function.  However, this patch instead simply folds
it into the caller, as it's only two lines anyway.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>