drm: remove drm_dev_to_irq from drivers

Only used in some legacy pci drivers, and dereferencing the PCI irq is
actually shorter ...

Since this removes all users for drm_dev_to_irq from the tree except
in drm_irq.c, move the inline helper in there. It'll disappear soon,
too.

v2: Polish commit message (Thierry)
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_irq.c

@@ -233,6 +233,11 @@ static void drm_irq_vgaarb_nokms(void *cookie, bool state)
 	}
 }
 
+static inline int drm_dev_to_irq(struct drm_device *dev)
+{
+	return dev->driver->bus->get_irq(dev);
+}
+
 /**
  * Install IRQ handler.
  *

drivers/gpu/drm/mga/mga_state.c

@@ -1020,7 +1020,7 @@ static int mga_getparam(struct drm_device *dev, void *data, struct drm_file *fil
 
 	switch (param->param) {
 	case MGA_PARAM_IRQ_NR:
-		value = drm_dev_to_irq(dev);
+		value = dev->pdev->irq;
 		break;
 	case MGA_PARAM_CARD_TYPE:
 		value = dev_priv->chipset;

drivers/gpu/drm/r128/r128_state.c

@@ -1594,7 +1594,7 @@ static int r128_getparam(struct drm_device *dev, void *data, struct drm_file *fi
 
 	switch (param->param) {
 	case R128_PARAM_IRQ_NR:
-		value = drm_dev_to_irq(dev);
+		value = dev->pdev->irq;
 		break;
 	default:
 		return -EINVAL;

drivers/gpu/drm/radeon/radeon_state.c

@@ -3054,7 +3054,7 @@ static int radeon_cp_getparam(struct drm_device *dev, void *data, struct drm_fil
 		if ((dev_priv->flags & RADEON_FAMILY_MASK) >= CHIP_R600)
 			value = 0;
 		else
-			value = drm_dev_to_irq(dev);
+			value = dev->pdev->irq;
 		break;
 	case RADEON_PARAM_GART_BASE:
 		value = dev_priv->gart_vm_start;

include/drm/drmP.h

@@ -1185,11 +1185,6 @@ static __inline__ int drm_core_check_feature(struct drm_device *dev,
 	return ((dev->driver->driver_features & feature) ? 1 : 0);
 }
 
-static inline int drm_dev_to_irq(struct drm_device *dev)
-{
-	return dev->driver->bus->get_irq(dev);
-}
-
 static inline void drm_device_set_unplugged(struct drm_device *dev)
 {
 	smp_wmb();