drm/exynos: Fix dma_parms allocation

Since commit 9495b7e9 ("driver core: platform: Initialize dma_parms
for platform devices") driver core handles allocation of the dma_parms
structure for platform device, so there is no need to manually allocate
nor free it.
Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_dma.c

@@ -31,23 +31,6 @@
 #define EXYNOS_DEV_ADDR_START	0x20000000
 #define EXYNOS_DEV_ADDR_SIZE	0x40000000
 
-static inline int configure_dma_max_seg_size(struct device *dev)
-{
-	if (!dev->dma_parms)
-		dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL);
-	if (!dev->dma_parms)
-		return -ENOMEM;
-
-	dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
-	return 0;
-}
-
-static inline void clear_dma_max_seg_size(struct device *dev)
-{
-	kfree(dev->dma_parms);
-	dev->dma_parms = NULL;
-}
-
 /*
  * drm_iommu_attach_device- attach device to iommu mapping
  *
@@ -69,10 +52,7 @@ static int drm_iommu_attach_device(struct drm_device *drm_dev,
 		return -EINVAL;
 	}
 
-	ret = configure_dma_max_seg_size(subdrv_dev);
-	if (ret)
-		return ret;
-
+	dma_set_max_seg_size(subdrv_dev, DMA_BIT_MASK(32));
 	if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) {
 		/*
 		 * Keep the original DMA mapping of the sub-device and
@@ -89,9 +69,6 @@ static int drm_iommu_attach_device(struct drm_device *drm_dev,
 		ret = iommu_attach_device(priv->mapping, subdrv_dev);
 	}
 
-	if (ret)
-		clear_dma_max_seg_size(subdrv_dev);
-
 	return ret;
 }
 
@@ -114,8 +91,6 @@ static void drm_iommu_detach_device(struct drm_device *drm_dev,
 		arm_iommu_attach_device(subdrv_dev, *dma_priv);
 	} else if (IS_ENABLED(CONFIG_IOMMU_DMA))
 		iommu_detach_device(priv->mapping, subdrv_dev);
-
-	clear_dma_max_seg_size(subdrv_dev);
 }
 
 int exynos_drm_register_dma(struct drm_device *drm, struct device *dev,