rockchip: usb: Migrate to use ofnode

Migrate to use ofnode_* instead of fdt_* so that we may able to use live
dt for usb udc driver.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/board.c b/arch/arm/mach-rockchip/board.c
index 8ca3463..c4b0b9d 100644
--- a/arch/arm/mach-rockchip/board.c
+++ b/arch/arm/mach-rockchip/board.c
@@ -61,28 +61,26 @@
 
 int board_usb_init(int index, enum usb_init_type init)
 {
-	int node;
+	ofnode node;
 	const char *mode;
 	bool matched = false;
-	const void *blob = gd->fdt_blob;
 
 	/* find the usb_otg node */
-	node = fdt_node_offset_by_compatible(blob, -1, "snps,dwc2");
-
-	while (node > 0) {
-		mode = fdt_getprop(blob, node, "dr_mode", NULL);
+	node = ofnode_by_compatible(ofnode_null(), "snps,dwc2");
+	while (ofnode_valid(node)) {
+		mode = ofnode_read_string(node, "dr_mode");
 		if (mode && strcmp(mode, "otg") == 0) {
 			matched = true;
 			break;
 		}
 
-		node = fdt_node_offset_by_compatible(blob, node, "snps,dwc2");
+		node = ofnode_by_compatible(node, "snps,dwc2");
 	}
 	if (!matched) {
 		debug("Not found usb_otg device\n");
 		return -ENODEV;
 	}
-	otg_data.regs_otg = fdtdec_get_addr(blob, node, "reg");
+	otg_data.regs_otg = ofnode_get_addr(node);
 
 	return dwc2_udc_probe(&otg_data);
 }