USB: serial: mos7840: fix remote wakeup

USB: serial: mos7840: fix remote wakeup

The driver was setting the device remote-wakeup feature during probe in
violation of the USB specification (which says it should only be set
just prior to suspending the device). This could potentially waste
power during suspend as well as lead to spurious wakeups.

Note that USB core would clear the remote-wakeup feature at first
resume.

Fixes: 3f5429746d91 ("USB: Moschip 7840 USB-Serial Driver")
Cc: stable <stable@vger.kernel.org>     # 2.6.19
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>