oldland: enable environment on MMC boot partition.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
oldland/spi: increase maximum frequency.

Decrease divider to 32 for increased SPI performance.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
env_fat: make sure env buffer is L1 aligned.

Prevents need for bounce buffers in FAT code.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>