qcacld-2.0: Use request manager for Class A stats

propagation from qcacld-3.0 to qcacld-2.0
We are transitioning to the new request manager framework. Change
wlan_hdd_get_classAstats() and hdd_get_class_a_statistics_cb() to
this framework.

Change-Id: I6cfa2155187e3d9ac4099f1e4480835917fd9ca6
CRs-Fixed: 2207553
Bug: 111289931
(cherry picked from commit 8122216c0708c0300174dcae7917352b5d145cd1)
2 files changed