net: ena: fix device destruction to gracefully free resources

When ena_destroy_device() is called from ena_suspend(), the device is
still reachable from the driver. Therefore, the driver can send a command
to the device to free all resources.
However, in all other cases of calling ena_destroy_device(), the device is
potentially in an error state and unreachable from the driver. In these
cases the driver must not send commands to the device.

The current implementation does not request resource freeing from the
device even when possible. We add the graceful parameter to
ena_destroy_device() to enable resource freeing when possible, and
use it in ena_suspend().

Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>