fman: insert the Fman firmware into the device tree

The Fman device tree node binding allows for the entire Fman firmware binary
data to be embedded in the device tree.  This eliminates the need to have
NOR flash mapped to Linux just so that the Fman driver can see the firmware.

The location of the Fman firmware is taken from the 'fman_ucode' environment
variable.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>