dm: Use access methods for dev/uclass private data

Most drivers use these access methods but a few do not. Update them.

In some cases the access is not permitted, so mark those with a FIXME tag
for the maintainer to check.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Pratyush Yadav <p.yadav@ti.com>
diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
index 99b5078..c9315dd 100644
--- a/lib/efi_loader/efi_device_path.c
+++ b/lib/efi_loader/efi_device_path.c
@@ -531,7 +531,7 @@
 	case UCLASS_ETH: {
 		struct efi_device_path_mac_addr *dp =
 			dp_fill(buf, dev->parent);
-		struct eth_pdata *pdata = dev->plat;
+		struct eth_pdata *pdata = dev_get_plat(dev);
 
 		dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 		dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;