qcacmn: Change QDF_MAX_AVAILABLE_CPU value
Currently QDF_MAX_AVAILABLE_CPU value is 8 for QCA_CONFIG_SMP
case, This hard coded value can result in out of bound issue
if available CPUs are greater than 8.
So to fix issue define QDF_MAX_AVAILABLE_CPU value to NR_CPUS.
CRs-Fixed: 3618754
Change-Id: Ic493aac48ac4a4d2fd983a294d45d86bb062fb61