octeontx2-af: Synchronize mcam rule list ops

commit 3e26a8c03bad5e7379318165d7410dbadabe3c0d from
git@git.assembla.com:cavium/WindRiver.linux.git

MCAM rules list maintained for all the mcam rules
installed is not gaurded by locks currently.
Hence prevent concurrent reading and writing
to rules list using mutex.

Change-Id: Ia859662f74d3ed35867822ec2101aa89db655254
Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/26750


Reviewed-by: Sunil Kovvuri Goutham <Sunil.Goutham@cavium.com>
Tested-by: Sunil Kovvuri Goutham <Sunil.Goutham@cavium.com>
Signed-off-by: Ruiqiang Hao <Ruiqiang.Hao@windriver.com>