H3 SPI has same architecture as A31 except FIFO capacity. To configure the buffer size separately, compatible property should be different. Optional DMA specifiers and example are added. Signed-off-by: Milo Kim <woogyom.kim@gmail.com> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Rob Herring <robh+dt@kernel.org> Signed-off-by: Mark Brown <broonie@kernel.org>