drm/i915: always use RPNSWREQ for turbo change requests

commit 89ba829e upstream.

Media turbo requests can either use RPVSWREQ or RPNSWREQ to indicate
what the interrupt handler should do.  Since we only deal with the
latter in our turbo code, make the media engine use that for turbo
requests.
Tested-by: Joe Bloggsian <joebloggsian@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/gpu/drm/i915/intel_display.c

@@ -8005,7 +8005,7 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
 	I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);
 	I915_WRITE(GEN6_RP_CONTROL,
 		   GEN6_RP_MEDIA_TURBO |
-		   GEN6_RP_MEDIA_HW_MODE |
+		   GEN6_RP_MEDIA_HW_NORMAL_MODE |
 		   GEN6_RP_MEDIA_IS_GFX |
 		   GEN6_RP_ENABLE |
 		   GEN6_RP_UP_BUSY_AVG |