i915: reprogram power monitoring registers on resume

Fixes issue where i915_gfx_val was reporting values several
orders of magnitude higher than physically possible (without
leaving scorch marks on my thighs at least.)

Signed-off-by: Kyle McMartin <kyle@redhat.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: stable@kernel.org
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/intel_drv.h

@@ -296,6 +296,7 @@ extern void intel_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
 extern void intel_init_clock_gating(struct drm_device *dev);
 extern void ironlake_enable_drps(struct drm_device *dev);
 extern void ironlake_disable_drps(struct drm_device *dev);
+extern void intel_init_emon(struct drm_device *dev);
 
 extern int intel_pin_and_fence_fb_obj(struct drm_device *dev,
 				      struct drm_gem_object *obj,