This "session-id" alogrithm is not required, and currently corrupts
the stored image whenever more the one "session" is required.
Signed-off-by: Steve Rae <srae@broadcom.com>
So far the fastboot code was only supporting MMC-backed devices for its
flashing operations (flash and erase).
Add a storage backend for NAND-backed devices.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>