msm: lpm_resources: Update rpm sleep data on notification

When lpm_resources receives a sleep data notification, the kvp data has
to be buffered into the existing buffer. If not updated, lpm_resources
chooses a mode where its local copy of the vote hasn't changed but the
vote from the originating driver has been updated.

Change-Id: Ie7dd734ede19463ae0be256ae78360705ca2c944
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>