drivers: ethernet: adin2111: add Open Alliance SPI support

Add Open Alliance spi protocol support.

Open Alliance is a chunk-based SPI protocol, based on sending
over SPI an ethernet frame divided in smaller chunks, using a
specific 32-bit header for each chunk transferred. All chunks
can be sent or received by a single dma transfer.

Default mode is set to Open Alliance SPI without protection,
since the adin2111 dev. board comes shipped this way.

Tested:
- Open Alliance SPI, no protection (default board shipped)
- Open Alliance SPI, protection
- Generic SPI, no crc
- Generic SPI, with crc8

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>