drm/amdgpu: add dm ip block for dcn 3.1.5

this patch adds dm ip block for dcn 3.1.5.
Signed-off-by: Yifan Zhang <yifan1.zhang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1373,6 +1373,7 @@ static int amdgpu_discovery_set_display_ip_blocks(struct amdgpu_device *adev)
 		case IP_VERSION(3, 0, 1):
 		case IP_VERSION(3, 1, 2):
 		case IP_VERSION(3, 1, 3):
+		case IP_VERSION(3, 1, 5):
 		case IP_VERSION(3, 1, 6):
 			amdgpu_device_ip_block_add(adev, &dm_ip_block);
 			break;