drm: kill drm_bus->bus_type

Completely unused. Hooray, midlayer mistakes that didn't cause work to
undo!

v2: Rebase on top of the recent tegra changes which added a host1x drm
bus.
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

@@ -317,7 +317,6 @@ void drm_pci_agp_destroy(struct drm_device *dev)
 }
 
 static struct drm_bus drm_pci_bus = {
-	.bus_type = DRIVER_BUS_PCI,
 	.get_irq = drm_pci_get_irq,
 	.get_name = drm_pci_get_name,
 	.set_busid = drm_pci_set_busid,

drivers/gpu/drm/drm_platform.c

@@ -123,7 +123,6 @@ static int drm_platform_set_busid(struct drm_device *dev, struct drm_master *mas
 }
 
 static struct drm_bus drm_platform_bus = {
-	.bus_type = DRIVER_BUS_PLATFORM,
 	.get_irq = drm_platform_get_irq,
 	.get_name = drm_platform_get_name,
 	.set_busid = drm_platform_set_busid,

drivers/gpu/drm/drm_usb.c

@@ -53,7 +53,6 @@ static int drm_usb_set_busid(struct drm_device *dev,
 }
 
 static struct drm_bus drm_usb_bus = {
-	.bus_type = DRIVER_BUS_USB,
 	.get_irq = drm_usb_get_irq,
 	.get_name = drm_usb_get_name,
 	.set_busid = drm_usb_set_busid,

drivers/gpu/drm/tegra/bus.c

@@ -37,7 +37,6 @@ static int drm_host1x_set_busid(struct drm_device *dev,
 }
 
 static struct drm_bus drm_host1x_bus = {
-	.bus_type = DRIVER_BUS_HOST1X,
 	.set_busid = drm_host1x_set_busid,
 };
 

include/drm/drmP.h

@@ -143,11 +143,6 @@ int drm_err(const char *func, const char *format, ...);
 #define DRIVER_PRIME       0x4000
 #define DRIVER_RENDER      0x8000
 
-#define DRIVER_BUS_PCI 0x1
-#define DRIVER_BUS_PLATFORM 0x2
-#define DRIVER_BUS_USB 0x3
-#define DRIVER_BUS_HOST1X 0x4
-
 /***********************************************************************/
 /** \name Begin the DRM... */
 /*@{*/
@@ -731,7 +726,6 @@ struct drm_master {
 #define DRM_SCANOUTPOS_ACCURATE     (1 << 2)
 
 struct drm_bus {
-	int bus_type;
 	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);