drm/i915: s/dpio_lock/sb_lock/

Rename dpio_lock to sb_lock to inform the reader that its primary
purpose is to protect the sideband mailbox rather than some DPIO
state.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_dsi_pll.c b/drivers/gpu/drm/i915/intel_dsi_pll.c
index 9688d99..d20cf37 100644
--- a/drivers/gpu/drm/i915/intel_dsi_pll.c
+++ b/drivers/gpu/drm/i915/intel_dsi_pll.c
@@ -244,7 +244,7 @@
 
 	DRM_DEBUG_KMS("\n");
 
-	mutex_lock(&dev_priv->dpio_lock);
+	mutex_lock(&dev_priv->sb_lock);
 
 	vlv_configure_dsi_pll(encoder);
 
@@ -258,11 +258,11 @@
 	if (wait_for(vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL) &
 						DSI_PLL_LOCK, 20)) {
 
-		mutex_unlock(&dev_priv->dpio_lock);
+		mutex_unlock(&dev_priv->sb_lock);
 		DRM_ERROR("DSI PLL lock failed\n");
 		return;
 	}
-	mutex_unlock(&dev_priv->dpio_lock);
+	mutex_unlock(&dev_priv->sb_lock);
 
 	DRM_DEBUG_KMS("DSI PLL locked\n");
 }
@@ -274,14 +274,14 @@
 
 	DRM_DEBUG_KMS("\n");
 
-	mutex_lock(&dev_priv->dpio_lock);
+	mutex_lock(&dev_priv->sb_lock);
 
 	tmp = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
 	tmp &= ~DSI_PLL_VCO_EN;
 	tmp |= DSI_PLL_LDO_GATE;
 	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, tmp);
 
-	mutex_unlock(&dev_priv->dpio_lock);
+	mutex_unlock(&dev_priv->sb_lock);
 }
 
 static void assert_bpp_mismatch(int pixel_format, int pipe_bpp)
@@ -319,10 +319,10 @@
 
 	DRM_DEBUG_KMS("\n");
 
-	mutex_lock(&dev_priv->dpio_lock);
+	mutex_lock(&dev_priv->sb_lock);
 	pll_ctl = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
 	pll_div = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_DIVIDER);
-	mutex_unlock(&dev_priv->dpio_lock);
+	mutex_unlock(&dev_priv->sb_lock);
 
 	/* mask out other bits and extract the P1 divisor */
 	pll_ctl &= DSI_PLL_P1_POST_DIV_MASK;