CHROMIUM: mwifiex: disconnect the device before entering suspend state

CHROMIUM: mwifiex: disconnect the device before entering suspend state

By default, device is disconnected before entering suspend state.
User can keep the connection alive by using module parameter
"disconnect_on_suspend=0".

BUG=chrome-os-partner:12164
TEST=manual,
  1. Boot device on battery and associated to AP
  2. Suspend
  3. Measure current to WLAN <=1mA ( deep-sleep state )
  4. Resume and device re-connects to AP successfully
  5. echo 0 > /sys/module/mwifiex/parameters/disconnect_on_suspend
  6. Measure current to WLAN <=10mA ( IEEE PS state )
  7. Resume and device re-connect to AP successfully

Change-Id: Iaf633d41e1a0cf2fab2dad9ff16dc39d04e87abf
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Todd Broch <tbroch@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/32294
Reviewed-by: Gary Morain <gmorain@chromium.org>