Currently HDD passes the CDS context to sme_get_rssi(), which in turn
passes it to csr_get_rssi(), which in turn uses it to populate the
p_cds_context field in the tAniGetRssiReq message. Upon processing of
this message by csr_update_rssi() the p_cds_context is checked for
NULL but is otherwise unused. Since the CDS context is not needed,
remove it from all of the RSSI APIs.
Change-Id: I5836e3192205576f6ff4614a29356e73fe674848
CRs-Fixed: 2116954
8bd23354cf