arm64: dts: rockchip: Set dr_mode to "host" for OTG on rk3328-roc-cc

arm64: dts: rockchip: Set dr_mode to "host" for OTG on rk3328-roc-cc

The board has a standard USB A female port connected to the USB OTG
controller's data pins. Set dr_mode in the OTG controller node to
indicate this usage, instead of having the implementation guess.

Fixes: 2171f4fdac06 ("arm64: dts: rockchip: add roc-rk3328-cc board")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20201126073336.30794-2-wens@kernel.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>