rockchip: rk3036: enable rockusb support on rk3036 based device

Rockchip Rockusb driver already merged. So we enable rockusb
support on rk3036 based device.

Signed-off-by: Eddie Cai <eddie.cai.linux@gmail.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>