rockchip: nanopi-r4s: Drop ROCKCHIP_OTP

The NanoPi R4S has an RK3399 SoC, which has efuse supported by
ROCKCHIP_EFUSE, not ROCKCHIP_OTP.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Dragan Simic <dsimic@manjaro.org>