qcacld-3.0: Remove hdd_checkandupdate_phymode() prototype

wlan_hdd_main.h exports hdd_checkandupdate_phymode() but the function
is no longer present, so remove the obsolete prototype.

Change-Id: I48afc44a1f4a4fe433278e868de9227a52c5fd78
CRs-Fixed: 2106839

core/hdd/inc/wlan_hdd_main.h

@@ -1991,7 +1991,6 @@ bool wlan_hdd_validate_modules_state(struct hdd_context *hdd_ctx);
 struct qdf_mac_addr *
 hdd_wlan_get_ibss_mac_addr_from_staid(struct hdd_adapter *pAdapter,
 				      uint8_t staIdx);
-void hdd_checkandupdate_phymode(struct hdd_context *hdd_ctx);
 #ifdef MSM_PLATFORM
 /**
  * hdd_bus_bw_compute_timer_start() - start the bandwidth timer