octeontx2-vf: Add support for adaptive interrupt coalescing

Fixes: 6e144b47 (octeontx2-pf: Add support for adaptive interrupt coalescing)
Added support for VF interfaces as well.

Signed-off-by: Suman Ghosh <sumang@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>