dm: gpio: Add live tree support

Add support for requesting GPIOs with a live device tree.

This involves adjusting the function signature for the legacy function
gpio_request_by_name_nodev(), so fix up all callers.

Signed-off-by: Simon Glass <sjg@chromium.org>
Fixes to stm32f746-disco.c:
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index c4e2cd7..8bc3828 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -1663,7 +1663,7 @@
 			chip->sels[i].rb.type = RB_NATIVE;
 			chip->sels[i].rb.info.nativeid = tmp;
 		} else {
-			ret = gpio_request_by_name_nodev(blob, node,
+			ret = gpio_request_by_name_nodev(offset_to_ofnode(node),
 						"rb-gpios", i,
 						&chip->sels[i].rb.info.gpio,
 						GPIOD_IS_IN);