pub fn new(spi_dma: SpiDma<'d, Dm>, rx_buf: DmaRxBuf, tx_buf: DmaTxBuf) -> Self {
            Self {
                spi_dma,
                rx_buf,
                tx_buf,
            }
        }
Creates a new `SpiDmaBus` with the specified SPI instance and DMA
buffers.
esp-hal/src/spi/master.rs