Add support for firmware update through the devlink interface.
This update copies the firmware object into the device, asks
the current firmware to install it, then asks the firmware to
select the new firmware for the next boot-up.

The install and select steps are launched as asynchronous
requests, which are then followed up with status request
commands.  These status request commands will be answered with
an EAGAIN return value and will try again until the request
has completed or reached the timeout specified.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>