drm/i915: VLV has force wake

This was omitted from

commit b7884eb4
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Mon Jun 4 11:18:15 2012 +0200

    drm/i915: hold forcewake around ring hw init

which introduced the ->has_force_wake flag.

Note that this only enables the above w/a hack.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Put some interesting stuff into the empty commit message.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.c

@@ -275,6 +275,7 @@ static const struct intel_device_info intel_valleyview_m_info = {
 	.has_blt_ring = 1,
 	.is_valleyview = 1,
 	.display_mmio_offset = VLV_DISPLAY_BASE,
+	.has_force_wake = 1,
 };
 
 static const struct intel_device_info intel_valleyview_d_info = {
@@ -285,6 +286,7 @@ static const struct intel_device_info intel_valleyview_d_info = {
 	.has_blt_ring = 1,
 	.is_valleyview = 1,
 	.display_mmio_offset = VLV_DISPLAY_BASE,
+	.has_force_wake = 1,
 };
 
 static const struct intel_device_info intel_haswell_d_info = {