Split the logic for progamming each LUT out of broadwell_load_luts(), so
we can reuse part of it for geminilake.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1485429865-10687-4-git-send-email-ander.conselvan.de.oliveira@intel.com