Macro avr_hal_generic::impl_spi

macro_rules! impl_spi {
    (
        hal: $HAL:ty,
        peripheral: $SPI:ty,
        sclk: $sclkpin:ty,
        mosi: $mosipin:ty,
        miso: $misopin:ty,
        cs: $cspin:ty,
    ) => { ... };
}

Implement traits for a SPI interface