octeontx2-pf: disable preemption while using per_cpu pointer

commit 8e4eeb142a03dbd69dfc6cb487d45e42030c2418 from
git@git.assembla.com:cavium/WindRiver.linux.git

Current code uses per_cpu pointer to get the lmtst_id mapped to the core
on which aura_free() is executed. Using per_cpu pointer without
preemption disable will cause mismatch between lmtst_id and core on
which pointer gets freed. Hence disable preemption around aura_free.

Signed-off-by: Geetha sowjanya <gakula@marvell.com>
Change-Id: I5b81a428a9f44944e50f4c34d2c3d0663aa7668b
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/65316


Reviewed-by: Geethasowjanya Akula <Geethasowjanya.Akula@cavium.com>
Tested-by: sa_ip-sw-jenkins <sa_ip-sw-jenkins@marvell.com>
Signed-off-by: Ruiqiang Hao <Ruiqiang.Hao@windriver.com>