msm: veth_ipa: Adding support for LPM and on/off events for veth_ipa driver

The support for different events such as LPM, carrier on/off,
interface up/down etc is supported with this check in.
The corresponding changes are required in the BE driver
for this change to take into effect.

Change-Id: Ia8086336e732715044bd432a65e3ca344ffdadd9
Acked-by: Sriragh Karat <skarat@qti.qualcomm.com>
Signed-off-by: Bojun Pan <bojunp@codeaurora.org>