regmap: change regmap_init_mem() to take ofnode instead udevice

Currently, regmap_init_mem() takes a udevice. This requires the node
has already been associated with a device. It prevents syscon/regmap
from behaving like those in Linux.

Change the first argumenet to take a device node.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/ram/rockchip/sdram_rk3188.c b/drivers/ram/rockchip/sdram_rk3188.c
index 91edc5a..3774abf 100644
--- a/drivers/ram/rockchip/sdram_rk3188.c
+++ b/drivers/ram/rockchip/sdram_rk3188.c
@@ -839,7 +839,7 @@
 		printf("%s: Cannot read rockchip,sdram-params\n", __func__);
 		return -EINVAL;
 	}
-	ret = regmap_init_mem(dev, &params->map);
+	ret = regmap_init_mem(dev_ofnode(dev), &params->map);
 	if (ret)
 		return ret;
 #endif