gpu: ipu-v3: don't depend on DRM being enabled

The PRE/PRG drivers, which need the DRM infrastructure, are only used
from the output path, so we skip building them into the ipu-v3 driver
if CONFIG_DRM is not enabled.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/ipu-v3/Makefile

@@ -2,4 +2,8 @@ obj-$(CONFIG_IMX_IPUV3_CORE) += imx-ipu-v3.o
 
 imx-ipu-v3-objs := ipu-common.o ipu-cpmem.o ipu-csi.o ipu-dc.o ipu-di.o \
 		ipu-dp.o ipu-dmfc.o ipu-ic.o ipu-image-convert.o \
-		ipu-pre.o ipu-prg.o ipu-smfc.o ipu-vdi.o
+		ipu-smfc.o ipu-vdi.o
+
+ifdef CONFIG_DRM
+	imx-ipu-v3-objs += ipu-pre.o ipu-prg.o
+endif

drivers/gpu/ipu-v3/ipu-common.c

@@ -1401,7 +1401,8 @@ static int ipu_probe(struct platform_device *pdev)
 
 	ipu->id = of_alias_get_id(np, "ipu");
 
-	if (of_device_is_compatible(np, "fsl,imx6qp-ipu")) {
+	if (of_device_is_compatible(np, "fsl,imx6qp-ipu") &&
+	    IS_ENABLED(CONFIG_DRM)) {
 		ipu->prg_priv = ipu_prg_lookup_by_phandle(&pdev->dev,
 							  "fsl,prg", ipu->id);
 		if (!ipu->prg_priv)
@@ -1538,8 +1539,10 @@ static struct platform_driver imx_ipu_driver = {
 };
 
 static struct platform_driver * const drivers[] = {
+#if IS_ENABLED(CONFIG_DRM)
 	&ipu_pre_drv,
 	&ipu_prg_drv,
+#endif
 	&imx_ipu_driver,
 };