octeontx2-af: Verify NPA/SSO/NIX PF_FUNC mapping

While mapping a NIX LF to a NPA LF attached PF_FUNC or
SSO LF attached PF_FUNC, verify if PF_FUNC is valid and
if that PF_FUNC has a LF of that block attached to it or not.

Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>