octeontx2-af: Remove MAC address validation check

commit 3e33c3be6772e3a60035fda9b4de532ace0c31c8 from
git@git.assembla.com:cavium/WindRiver.linux.git

As part of klockwork fixes, a validation check was added to
avoid MAC address with value 0. But that is a valid source
MAC address for PFC packets. Hence removing the validation
check.

Signed-off-by: Suman Ghosh <sumang@marvell.com>
Change-Id: I3187344a2e2d6a96efdcb65a99b762ff284c1efb
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/120576
Tested-by: sa_ip-sw-jenkins <sa_ip-sw-jenkins@marvell.com>
Reviewed-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: Ruiqiang Hao <Ruiqiang.Hao@windriver.com>