octeontx2-af: invalidate GWC before accessing workslot

commit  70350f35f25b9eda7304abe8bd2b52ac0dec8b5d from
https://git.assembla.com/cavium/WindRiver.linux.git

Invalidate APs GWC(Getwork Cache) for the Workslot that is being
reset or being used for flushing work from groups.
Prefix invalidate with a full system barrier to make sure all the
in-flights complete before invalidate.

Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
Change-Id: I31aabf202410445e5821d5e80ba67394505d49fe
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/51881
Tested-by: sa_ip-sw-jenkins <sa_ip-sw-jenkins@marvell.com>
Reviewed-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: Meng Li <Meng.Li@windriver.com>
Signed-off-by: Ruiqiang Hao <Ruiqiang.Hao@windriver.com>