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/drivers/spi/pl022_spi.c b/drivers/spi/pl022_spi.c
index 179582c..133363e 100644
--- a/drivers/spi/pl022_spi.c
+++ b/drivers/spi/pl022_spi.c
@@ -288,7 +288,7 @@
 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
 static int pl022_spi_of_to_plat(struct udevice *bus)
 {
-	struct pl022_spi_pdata *plat = bus->plat;
+	struct pl022_spi_pdata *plat = dev_get_plat(bus);
 	const void *fdt = gd->fdt_blob;
 	int node = dev_of_offset(bus);
 	struct clk clkdev;