drm: remove unused dma support remnants.

These are unused since the gamma driver was dropped, they 
cause problems with the via driver (coming soon).
Signed-off-by: Dave Airlie <airlied@linux.ie>

drivers/char/drm/drmP.h

@@ -458,13 +458,6 @@ typedef struct drm_device_dma {
 		_DRM_DMA_USE_SG  = 0x02
 	} flags;
 
-	/** \name DMA support */
-	/*@{*/
-	drm_buf_t	  *this_buffer;	/**< Buffer being sent */
-	drm_buf_t	  *next_buffer; /**< Selected buffer to send */
-	drm_queue_t	  *next_queue;	/**< Queue from which buffer selected*/
-	wait_queue_head_t waiting;	/**< Processes waiting on free bufs */
-	/*@}*/
 } drm_device_dma_t;
 
 /** 

drivers/char/drm/drm_irq.h

@@ -117,10 +117,6 @@ int DRM(irq_install)( drm_device_t *dev )
 
 	DRM_DEBUG( "%s: irq=%d\n", __FUNCTION__, dev->irq );
 
-	dev->dma->next_buffer = NULL;
-	dev->dma->next_queue = NULL;
-	dev->dma->this_buffer = NULL;
-
 	if (drm_core_check_feature(dev, DRIVER_IRQ_VBL)) {
 		init_waitqueue_head(&dev->vbl_queue);