Macro async_embedded_traits::impl_delay_us_for_us_u64

macro_rules! impl_delay_us_for_us_u64 {
    ($delay:ty) => { ... };
}

Implement AsyncDelayUs<u32>, AsyncDelayUs<u16>, AsyncDelayUs<u8> and AsyncDelayUs<i32> based on the AsyncDelayUs<u64> implementation.