net: ethtool: add support for reset of AP inside NIC interface.

Add ETH_RESET_AP to reset the application processor(s) inside the NIC
interface.

Current ETH_RESET_MGMT supports a management processor inside this NIC.
This is typically used for remote NIC management purposes.

Application processors exist inside some SmartNICs to run various
applications inside the NIC processor - be it a simple algorithm without
an OS to as complex as hosting multiple VMs.

Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>