linux-phytec-ti

atm: fore200e: Do not drop const qualifier

The data member of structure firmware is const and this constness is
dropped by some cast.
This patch add some const for keeping the const information.

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>