net: ena: add hardware hints capability to the driver

net: ena: add hardware hints capability to the driver

BugLink: http://bugs.launchpad.net/bugs/1701575
With this patch, ENA device can update the ena driver about
the desired timeout values:
These values are part of the "hardware hints" which are transmitted
to the driver as Asynchronous event through ENA async
event notification queue.

In case the ENA device does not support this capability,
the driver will use its own default values.

Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 82ef30f13be0b4fea70a9c6215f7cff40bb3be63 net-next)
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>