msm: ipa4: Fix to disable the napi when rmnet ipa interface going down

Because of napi not disabled during rmnet ipa interface going down,
when interface coming up napi will be in wrong state, it leads to
device assert. Added changed to disable napi for the rmnet_ipa
interface when the interface goes down.

Change-Id: Ia6c7cd6fe9f60c58ffd178dbbf877ab3b38a2f4b
Acked-by: Ashok Vuyyuru <avuyyuru@qti.qualcomm.com>
Signed-off-by: Mohammed Javid <mjavid@codeaurora.org>