am33xx: board: probe misc drivers to register musb devices

MUSB wrapper driver is bound as MISC device and underlying usb
devices are bind to usb drivers based on dr_mode, so probing the
MISC wrapper driver to register musb devices.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-omap2/am33xx/board.c b/arch/arm/mach-omap2/am33xx/board.c
index 80b729a..2ce7790 100644
--- a/arch/arm/mach-omap2/am33xx/board.c
+++ b/arch/arm/mach-omap2/am33xx/board.c
@@ -197,6 +197,13 @@
 	musb_register(&otg1_plat, &otg1_board_data,
 		(void *)USB1_OTG_BASE);
 #endif
+#else
+	struct udevice *dev;
+	int ret;
+
+	ret = uclass_first_device(UCLASS_MISC, &dev);
+	if (ret || !dev)
+		return ret;
 #endif
 	return 0;
 }