i965: Move brw_setup_tex_for_precompile to brw_program.[ch].

i965: Move brw_setup_tex_for_precompile to brw_program.[ch].

This living in brw_fs.{h,cpp} is a historical artifact of us supporting
texturing for fragment shaders before any other stages.  It's kind of
awkward given that we use it for all stages.

This avoids having to include brw_fs.h in geometry shader code in order
to access this function.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Chris Forbes <chrisf@ijw.co.nz>