octeontx2-pf: Set NIX1_RX interface for backpressure

commit 93d956c82303c4ba05cbe4b58d69828c95868c5f from
git@git.assembla.com:cavium/WindRiver.linux.git

To enable NPA aura backpressure to NIX block receive
interface the NIX RX interface either NIX0_RX or NIX1_RX
need to be set in aura context. If NIX1 LF is attached
to PF or VF then use NIX1_RX otherwise NIX0_RX.

Change-Id: I46c2b39351f972b14a7c1b1de1ce842baef27281
Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/38543


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