cdc_ether: fix autosuspend for mbm devices

cdc_ether: fix autosuspend for mbm devices

[ Upstream commit 55964d72d63b15df49a5df11ef91dc8601270815 ]

Autosuspend works until you bring the wwan interface up, then the
device does not enter autosuspend anymore.

The following patch fixes the problem by setting the .manage_power
field in the mbm_info struct to the same as in the cdc_info struct
(cdc_manager_power).

Signed-off-by: Torgny Johansson <torgny.johansson@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>