drm/amdgpu: Prefer dev_warn over printk

Fix the below warning:

WARNING: Prefer [subsystem eg: netdev]_warn([subsystem]dev, ... then
dev_warn(dev, ... then pr_warn(...  to printk(KERN_WARNING ...

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c

@@ -973,7 +973,7 @@ static int gmc_v10_0_sw_init(void *handle)
 
 	r = dma_set_mask_and_coherent(adev->dev, DMA_BIT_MASK(44));
 	if (r) {
-		printk(KERN_WARNING "amdgpu: No suitable DMA available.\n");
+		dev_warn(adev->dev, "amdgpu: No suitable DMA available.\n");
 		return r;
 	}
 

drivers/gpu/drm/amd/amdgpu/gmc_v11_0.c

@@ -824,7 +824,7 @@ static int gmc_v11_0_sw_init(void *handle)
 
 	r = dma_set_mask_and_coherent(adev->dev, DMA_BIT_MASK(44));
 	if (r) {
-		printk(KERN_WARNING "amdgpu: No suitable DMA available.\n");
+		dev_warn(adev->dev, "amdgpu: No suitable DMA available.\n");
 		return r;
 	}
 

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

@@ -2149,7 +2149,7 @@ static int gmc_v9_0_sw_init(void *handle)
 	dma_addr_bits = adev->ip_versions[GC_HWIP][0] >= IP_VERSION(9, 4, 2) ? 48:44;
 	r = dma_set_mask_and_coherent(adev->dev, DMA_BIT_MASK(dma_addr_bits));
 	if (r) {
-		printk(KERN_WARNING "amdgpu: No suitable DMA available.\n");
+		dev_warn(adev->dev, "amdgpu: No suitable DMA available.\n");
 		return r;
 	}
 	adev->need_swiotlb = drm_need_swiotlb(dma_addr_bits);