83xx/fdt_support: let user specifiy FSL USB Dual-Role controller role

Linux understands "host" (default), "peripheral" and "otg" (broken).
Though, U-Boot doesn't restrict dr_mode variable to these values (think
of renames in future).

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>

board/freescale/mpc837xerdb/mpc837xerdb.c

@@ -197,5 +197,6 @@ void ft_board_setup(void *blob, bd_t *bd)
 	ft_pci_setup(blob, bd);
 #endif
 	ft_cpu_setup(blob, bd);
+	fdt_fixup_dr_usb(blob, bd);
 }
 #endif /* CONFIG_OF_BOARD_SETUP */