wlan: sap: Use request manager for Class A stats

We are transitioning to the new request manager framework. Change
wlan_hdd_get_classAstats_for_station and hdd_GetClassA_statisticsCB()
to this framework.

Change-Id: I90724ff672bfea7edbba66eb32371dca71bd8681
CRs-Fixed: 2207695
3 files changed