timer: nomadik-mtu: Use dev_read_addr_ptr()

Simplify the code a bit by using dev_read_addr_ptr() instead of
dev_read_addr(). This avoids having to cast explicitly to the
struct nomadik_mtu_regs.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/timer/nomadik-mtu-timer.c b/drivers/timer/nomadik-mtu-timer.c
index 417b419..4d24de1 100644
--- a/drivers/timer/nomadik-mtu-timer.c
+++ b/drivers/timer/nomadik-mtu-timer.c
@@ -67,14 +67,11 @@
 	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
 	struct nomadik_mtu_priv *priv = dev_get_priv(dev);
 	struct nomadik_mtu_regs *mtu;
-	fdt_addr_t addr;
 	u32 prescale;
 
-	addr = dev_read_addr(dev);
-	if (addr == FDT_ADDR_T_NONE)
+	mtu = dev_read_addr_ptr(dev);
+	if (!mtu)
 		return -EINVAL;
-
-	mtu = (struct nomadik_mtu_regs *)addr;
 	priv->timer = mtu->timers; /* Use first timer */
 
 	if (!uc_priv->clock_rate)