drm/exynos: changed buffer structure.

the purpose of this patch is to consider IOMMU support in the future.
EXYNOS4 SoC supports IOMMU also so the address for DMA could be
physical address with IOMMU or device address with IOMMU.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
index 1575e5f..38a6f1d 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
@@ -79,8 +79,8 @@
  * @scan_flag: interlace or progressive way.
  *	(it could be DRM_MODE_FLAG_*)
  * @bpp: pixel size.(in bit)
- * @paddr: bus(accessed by dma) physical memory address to this overlay
- *		and this is physically continuous.
+ * @dma_addr: bus(accessed by dma) address to the memory region allocated
+ *	for a overlay.
  * @vaddr: virtual memory addresss to this overlay.
  * @default_win: a window to be enabled.
  * @color_key: color key on or off.
@@ -108,7 +108,7 @@
 	unsigned int scan_flag;
 	unsigned int bpp;
 	unsigned int pitch;
-	dma_addr_t paddr;
+	dma_addr_t dma_addr;
 	void __iomem *vaddr;
 
 	bool default_win;