drm/i915/chv: Set min freq to efficient frequency on chv

After feedback from the hardware team, now we set the GPU min/idel freq to RPe.
Punit is expecting us to operate GPU between Rpe & Rp0. If we drop the
frequency to RPn, punit is failing to change the vgg input voltage to
minimum :(

Since Punit validates the rps range [RPe, RP0]. This patch
removes unused cherryview_rps_min_freq function.

v2: Change commit message

v3: set min_freq before idle_freq (chris)

v4: Squash 'Remove unused rps min function' patch
Signed-off-by: Deepak S <deepak.s@linux.intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -4743,24 +4743,6 @@ static int cherryview_rps_guar_freq(struct drm_i915_private *dev_priv)
 	return rp1;
 }
 
-static int cherryview_rps_min_freq(struct drm_i915_private *dev_priv)
-{
-	struct drm_device *dev = dev_priv->dev;
-	u32 val, rpn;
-
-	if (dev->pdev->revision >= 0x20) {
-		val = vlv_punit_read(dev_priv, FB_GFX_FMIN_AT_VMIN_FUSE);
-		rpn = ((val >> FB_GFX_FMIN_AT_VMIN_FUSE_SHIFT) &
-		       FB_GFX_FREQ_FUSE_MASK);
-	} else { /* For pre-production hardware */
-		val = vlv_punit_read(dev_priv, PUNIT_GPU_STATUS_REG);
-		rpn = ((val >> PUNIT_GPU_STATIS_GFX_MIN_FREQ_SHIFT) &
-		       PUNIT_GPU_STATUS_GFX_MIN_FREQ_MASK);
-	}
-
-	return rpn;
-}
-
 static int valleyview_rps_guar_freq(struct drm_i915_private *dev_priv)
 {
 	u32 val, rp1;
@@ -5012,7 +4994,8 @@ static void cherryview_init_gt_powersave(struct drm_device *dev)
 			 intel_gpu_freq(dev_priv, dev_priv->rps.rp1_freq),
 			 dev_priv->rps.rp1_freq);
 
-	dev_priv->rps.min_freq = cherryview_rps_min_freq(dev_priv);
+	/* PUnit validated range is only [RPe, RP0] */
+	dev_priv->rps.min_freq = dev_priv->rps.efficient_freq;
 	DRM_DEBUG_DRIVER("min GPU freq: %d MHz (%u)\n",
 			 intel_gpu_freq(dev_priv, dev_priv->rps.min_freq),
 			 dev_priv->rps.min_freq);