devlink: Add health recover command

Add devlink health recover command to the uapi, in order to allow the user
to execute a recover operation over a specific reporter.

Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>