msm: ipa: Fix to un-registering of SSR notifier object

Make changes to pass valid handle to SSR notifier un-register API.

Change-Id: Idd2e61fd150d77912e1c7627f4d350100ba91785
Acked-by: Chaitanya Pratapa <cpratapa@qti.qualcomm.com>
Signed-off-by: Ravinder Konka <rkonka@codeaurora.org>