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/serial/altera_uart.c b/drivers/serial/altera_uart.c
index a3efa1e..b18be6e 100644
--- a/drivers/serial/altera_uart.c
+++ b/drivers/serial/altera_uart.c
@@ -32,7 +32,7 @@
 
 static int altera_uart_setbrg(struct udevice *dev, int baudrate)
 {
-	struct altera_uart_plat *plat = dev->plat;
+	struct altera_uart_plat *plat = dev_get_plat(dev);
 	struct altera_uart_regs *const regs = plat->regs;
 	u32 div;
 
@@ -44,7 +44,7 @@
 
 static int altera_uart_putc(struct udevice *dev, const char ch)
 {
-	struct altera_uart_plat *plat = dev->plat;
+	struct altera_uart_plat *plat = dev_get_plat(dev);
 	struct altera_uart_regs *const regs = plat->regs;
 
 	if (!(readl(&regs->status) & ALTERA_UART_TRDY))
@@ -57,7 +57,7 @@
 
 static int altera_uart_pending(struct udevice *dev, bool input)
 {
-	struct altera_uart_plat *plat = dev->plat;
+	struct altera_uart_plat *plat = dev_get_plat(dev);
 	struct altera_uart_regs *const regs = plat->regs;
 	u32 st = readl(&regs->status);
 
@@ -69,7 +69,7 @@
 
 static int altera_uart_getc(struct udevice *dev)
 {
-	struct altera_uart_plat *plat = dev->plat;
+	struct altera_uart_plat *plat = dev_get_plat(dev);
 	struct altera_uart_regs *const regs = plat->regs;
 
 	if (!(readl(&regs->status) & ALTERA_UART_RRDY))