dm: core: add dev_read_addr_ptr()

The dev_read_addr_ptr() mimics the behaviour of the devfdt_get_addr_ptr(),
retrieving the first address of the node's reg-property and returning
it as a pointer (or NULL on failure).

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/core/read.c

@@ -57,6 +57,13 @@ fdt_addr_t dev_read_addr(struct udevice *dev)
 	return dev_read_addr_index(dev, 0);
 }
 
+void *dev_read_addr_ptr(struct udevice *dev)
+{
+	fdt_addr_t addr = dev_read_addr(dev);
+
+	return (addr == FDT_ADDR_T_NONE) ? NULL : (void *)addr;
+}
+
 fdt_addr_t dev_read_addr_size(struct udevice *dev, const char *property,
 				fdt_size_t *sizep)
 {