Add driver_supported_features to host_host info which is a new API used to
communicate to the device which features are supported by the driver.

Add the interrupt_moderation bit to host_info->driver_supported_features
and enable it to signal the device that this driver supports interrupt
moderation properly.

Reserved bits are for features implemented in the future
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>