[media] media-device: fix builds when USB or PCI is compiled as module

Just checking ifdef CONFIG_USB is not enough, if the USB is compiled
as module. The same applies to PCI.

Tested with the following .config alternatives:

CONFIG_USB=m
CONFIG_MEDIA_CONTROLLER=y
CONFIG_MEDIA_SUPPORT=m
CONFIG_VIDEO_AU0828=m

CONFIG_USB=m
CONFIG_MEDIA_CONTROLLER=y
CONFIG_MEDIA_SUPPORT=y
CONFIG_VIDEO_AU0828=m

CONFIG_USB=y
CONFIG_MEDIA_CONTROLLER=y
CONFIG_MEDIA_SUPPORT=y
CONFIG_VIDEO_AU0828=m

CONFIG_USB=y
CONFIG_MEDIA_CONTROLLER=y
CONFIG_MEDIA_SUPPORT=y
CONFIG_VIDEO_AU0828=y

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index 6e43c95..3cfd7af 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -846,11 +846,11 @@
 }
 EXPORT_SYMBOL_GPL(media_device_find_devres);
 
+#if IS_ENABLED(CONFIG_PCI)
 void media_device_pci_init(struct media_device *mdev,
 			   struct pci_dev *pci_dev,
 			   const char *name)
 {
-#ifdef CONFIG_PCI
 	mdev->dev = &pci_dev->dev;
 
 	if (name)
@@ -866,16 +866,16 @@
 	mdev->driver_version = LINUX_VERSION_CODE;
 
 	media_device_init(mdev);
-#endif
 }
 EXPORT_SYMBOL_GPL(media_device_pci_init);
+#endif
 
+#if IS_ENABLED(CONFIG_USB)
 void __media_device_usb_init(struct media_device *mdev,
 			     struct usb_device *udev,
 			     const char *board_name,
 			     const char *driver_name)
 {
-#ifdef CONFIG_USB
 	mdev->dev = &udev->dev;
 
 	if (driver_name)
@@ -895,9 +895,9 @@
 	mdev->driver_version = LINUX_VERSION_CODE;
 
 	media_device_init(mdev);
-#endif
 }
 EXPORT_SYMBOL_GPL(__media_device_usb_init);
+#endif
 
 
 #endif /* CONFIG_MEDIA_CONTROLLER */