rockchip: adc: rockchip-saradc: use dev_read_addr_ptr

The fdt_addr_t and phys_addr_t size have been decoupled.
A 32bit CPU can expext 64-bit data from the device tree parser,
so use dev_read_addr_ptr in the rockchip-saradc.c file.
As we are there also streamline the error response to -EINVAL on return.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/drivers/adc/rockchip-saradc.c b/drivers/adc/rockchip-saradc.c
index 760f8fe..809486e 100644
--- a/drivers/adc/rockchip-saradc.c
+++ b/drivers/adc/rockchip-saradc.c
@@ -145,10 +145,10 @@
 	struct rockchip_saradc_data *data;
 
 	data = (struct rockchip_saradc_data *)dev_get_driver_data(dev);
-	priv->regs = (struct rockchip_saradc_regs *)dev_read_addr(dev);
-	if (priv->regs == (struct rockchip_saradc_regs *)FDT_ADDR_T_NONE) {
+	priv->regs = dev_read_addr_ptr(dev);
+	if (!priv->regs) {
 		pr_err("Dev: %s - can't get address!", dev->name);
-		return -ENODATA;
+		return -EINVAL;
 	}
 
 	priv->data = data;