qcacld-3.0: Add a check for WLM latency manager support

Currently there is no check for WLM latency manager support,
while setting the latency level which may lead to undefined behavior.

To address the above issue add a check for WLM latency manager support.

Change-Id: I03aebc1a87a5a40265eea1189503d73f35472644
CRs-Fixed: 2746738