octeontx2-af: Cleanup loopback device checks

commit b0fdb523a034e713e4ea64a878ecb7389cb4be51 from
git@git.assembla.com:cavium/WindRiver.linux.git

PCI device IDs of RVU device IDs are configurable and
RVU PF0's (ie AF's) are currently assumed as VFs that
identify loopback functionality ie LBKVFs. But in some
cases these VFs can be setup for different functionality.
Hence remove assumptions that AF's VFs are always LBK VFs
by renaming 'is_afvf' as 'is_lbkvf' explicitly and also
identify LBK VF using PCI dev ID. Similar change is done
for other VF types.

Signed-off-by: Geetha sowjanya <gakula@marvell.com>
Change-Id: I948d237efbc8467dc5f8ccfe8c396553e84c8b7f
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/120578
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>