qede: add support for selftests.

This patch adds the qede ethtool support for the following tests:
- interrupt test
- memory test
- register test
- clock test

Signed-off-by: Sudarsana Reddy Kalluru <sudarsana.kalluru@qlogic.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>