freedreno/ir3: always mov tex coords

freedreno/ir3: always mov tex coords

Always insert extra mov's for the tex coord into the fanin.  This
simplifies things a bit, and avoids a scenario where multiple sam
instructions can have mutually exclusive input's to it's fanin, for
example:

  1: TEX OUT[0].xy, IN[0].xyxx, SAMP[0], 2D
  2: TEX OUT[0].zw, IN[0].yxxx, SAMP[0], 2D

The CP pass can always remove the mov's that are not actually needed,
so better to start out with too many mov's in the front end, than not
enough.

Signed-off-by: Rob Clark <robclark@freedesktop.org>