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/tegra_nand.c b/drivers/mtd/nand/tegra_nand.c
index 5c9b485..c03c9cb 100644
--- a/drivers/mtd/nand/tegra_nand.c
+++ b/drivers/mtd/nand/tegra_nand.c
@@ -894,8 +894,8 @@
 	config->reg = (struct nand_ctlr *)fdtdec_get_addr(blob, node, "reg");
 	config->enabled = fdtdec_get_is_enabled(blob, node);
 	config->width = fdtdec_get_int(blob, node, "nvidia,nand-width", 8);
-	err = gpio_request_by_name_nodev(blob, node, "nvidia,wp-gpios", 0,
-				 &config->wp_gpio, GPIOD_IS_OUT);
+	err = gpio_request_by_name_nodev(offset_to_ofnode(node),
+			"nvidia,wp-gpios", 0, &config->wp_gpio, GPIOD_IS_OUT);
 	if (err)
 		return err;
 	err = fdtdec_get_int_array(blob, node, "nvidia,timing",