qcacld-3.0: Remove csr_get_phy_mode_from_bssDesc()

Function csr_get_phy_mode_from_bssDesc() no longer exists, but the
prototype is still present. Since it is obsolete, remove it.

Change-Id: Ib5a37e0468d3f6f2f5ed862c99d508aadb3afda0
CRs-Fixed: 2374838

core/sme/inc/csr_support.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011-2018 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2011-2019 The Linux Foundation. All rights reserved.
  *
  * Permission to use, copy, modify, and/or distribute this software for
  * any purpose with or without fee is hereby granted, provided that the
@@ -231,7 +231,6 @@ bool csr_is_privacy(tSirBssDescription *pSirBssDesc);
 tSirResultCodes csr_get_de_auth_rsp_status_code(tSirSmeDeauthRsp *pSmeRsp);
 uint32_t csr_get_frag_thresh(struct mac_context *mac_ctx);
 uint32_t csr_get_rts_thresh(struct mac_context *mac_ctx);
-eCsrPhyMode csr_get_phy_mode_from_bssDesc(tSirBssDescription *pSirBssDesc);
 uint32_t csr_get11h_power_constraint(struct mac_context *mac_ctx,
 				     tDot11fIEPowerConstraints *constraints);
 uint8_t csr_construct_rsn_ie(struct mac_context *mac, uint32_t sessionId,