uboot-imx

Revert "spi: atmel: Drop atmel_spi.h"

As we aren't quite able to convert some platforms with a very small size
limit in SPL yet, we need to revert this for now.

This reverts commit 37434db29be495ef41f204a97b8bf13b1418f97d.

Signed-off-by: Tom Rini <trini@konsulko.com>