drivers: i915: Fix BLC PWM register setup

There is an error in i915_read_blc_pwm_ctl, where the register values
are not being copied correctly.  BLC_PWM_CTL and BLC_PWM_CTL2 are
getting mixed up.  This patch fixes that so that saveBLC_PWM_CTL2 and
not saveBLC_PWM_CTL is copied to the BLC_PWM_CTL2 register.
Signed-off-by: Simon Que <sque@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_panel.c

@@ -141,8 +141,8 @@ static u32 i915_read_blc_pwm_ctl(struct drm_i915_private *dev_priv)
 			dev_priv->saveBLC_PWM_CTL2 = val;
 		} else if (val == 0) {
 			I915_WRITE(BLC_PWM_PCH_CTL2,
-				   dev_priv->saveBLC_PWM_CTL);
-			val = dev_priv->saveBLC_PWM_CTL;
+				   dev_priv->saveBLC_PWM_CTL2);
+			val = dev_priv->saveBLC_PWM_CTL2;
 		}
 	} else {
 		val = I915_READ(BLC_PWM_CTL);