powerpc/p2020rdb: fix the FDT_ERR_NOTFOUND issue

Because the function ft_board_setup() delete the USB2 device node, it
leads to can't find the device node and hung up.

In fact only P1020RDB needs to delete the USB2 node, this patch fixes
this issue.

Signed-off-by: Ying Zhang <b40530@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
1 file changed