Remove 6GHz capability query through HAL

It was decided to perform the check on the device support of 6GHz
through overlay configs instead of through HAL.
This commit removes the Hidl API changes that were used for that
check.

Bug: 145936758
Bug: 139354972
Test: Manual
Test: VTS test
Test: Unit test: hardware/interfaces/wifi/1.4/default/tests/runtests.sh
Change-Id: I81fdf603a668a71e3e875211367111fffee20e54
diff --git a/wifi/1.4/default/wifi_chip.h b/wifi/1.4/default/wifi_chip.h
index c76eabf..3323ade 100644
--- a/wifi/1.4/default/wifi_chip.h
+++ b/wifi/1.4/default/wifi_chip.h
@@ -197,9 +197,9 @@
     std::pair<WifiStatus, sp<IWifiP2pIface>> getP2pIfaceInternal(
         const std::string& ifname);
     WifiStatus removeP2pIfaceInternal(const std::string& ifname);
-    std::pair<WifiStatus, sp<IWifiStaIface>> createStaIfaceInternal();
+    std::pair<WifiStatus, sp<V1_3::IWifiStaIface>> createStaIfaceInternal();
     std::pair<WifiStatus, std::vector<hidl_string>> getStaIfaceNamesInternal();
-    std::pair<WifiStatus, sp<IWifiStaIface>> getStaIfaceInternal(
+    std::pair<WifiStatus, sp<V1_3::IWifiStaIface>> getStaIfaceInternal(
         const std::string& ifname);
     WifiStatus removeStaIfaceInternal(const std::string& ifname);
     std::pair<WifiStatus, sp<V1_0::IWifiRttController>>