Add support for a RVU PF/VF to enable, disable, configure
and shuffle MCAM entries via mbox commands. This patch adds
mailbox message formats and handling of these commands.

As of now otherthan validating MCAM entry index, info like
channel number e.t.c in MCAM config data sent by PF/VF are
not validated.

Also a max of 64 MCAM entries can be shuffled with a single
mbox command.
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>