octeontx2-af: Add support for multi channel in NIX promisc entry

This patch adds support for multi channel NIX promisc entry. Packets sent
on all those channels by the host should be received by the interface to
which those channels belong. Channel count, if greater than 1, should be
power of 2 as only one promisc entry is available for the interface. Key
mask is modified such that incoming packets from channel base to channel
count are directed to the same pci function.

Signed-off-by: Nalla, Pradeep <pnalla@marvell.com>
Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>