drm: remove bus->get_irq implementations

Now that they're all unused we can get rid of them, including the
dummy version in drm_usb.c.

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_pci.c

@@ -137,11 +137,6 @@ static int drm_get_pci_domain(struct drm_device *dev)
 	return pci_domain_nr(dev->pdev->bus);
 }
 
-static int drm_pci_get_irq(struct drm_device *dev)
-{
-	return dev->pdev->irq;
-}
-
 static const char *drm_pci_get_name(struct drm_device *dev)
 {
 	struct pci_driver *pdriver = dev->driver->kdriver.pci;
@@ -317,7 +312,6 @@ void drm_pci_agp_destroy(struct drm_device *dev)
 }
 
 static struct drm_bus drm_pci_bus = {
-	.get_irq = drm_pci_get_irq,
 	.get_name = drm_pci_get_name,
 	.set_busid = drm_pci_set_busid,
 	.set_unique = drm_pci_set_unique,

drivers/gpu/drm/drm_platform.c

@@ -68,11 +68,6 @@ static int drm_get_platform_dev(struct platform_device *platdev,
 	return ret;
 }
 
-static int drm_platform_get_irq(struct drm_device *dev)
-{
-	return platform_get_irq(dev->platformdev, 0);
-}
-
 static const char *drm_platform_get_name(struct drm_device *dev)
 {
 	return dev->platformdev->name;
@@ -123,7 +118,6 @@ static int drm_platform_set_busid(struct drm_device *dev, struct drm_master *mas
 }
 
 static struct drm_bus drm_platform_bus = {
-	.get_irq = drm_platform_get_irq,
 	.get_name = drm_platform_get_name,
 	.set_busid = drm_platform_set_busid,
 };

drivers/gpu/drm/drm_usb.c

@@ -36,11 +36,6 @@ int drm_get_usb_dev(struct usb_interface *interface,
 }
 EXPORT_SYMBOL(drm_get_usb_dev);
 
-static int drm_usb_get_irq(struct drm_device *dev)
-{
-	return 0;
-}
-
 static const char *drm_usb_get_name(struct drm_device *dev)
 {
 	return "USB";
@@ -53,7 +48,6 @@ static int drm_usb_set_busid(struct drm_device *dev,
 }
 
 static struct drm_bus drm_usb_bus = {
-	.get_irq = drm_usb_get_irq,
 	.get_name = drm_usb_get_name,
 	.set_busid = drm_usb_set_busid,
 };

include/drm/drmP.h

@@ -726,7 +726,6 @@ struct drm_master {
 #define DRM_SCANOUTPOS_ACCURATE     (1 << 2)
 
 struct drm_bus {
-	int (*get_irq)(struct drm_device *dev);
 	const char *(*get_name)(struct drm_device *dev);
 	int (*set_busid)(struct drm_device *dev, struct drm_master *master);
 	int (*set_unique)(struct drm_device *dev, struct drm_master *master,