[WifiCoex] Add WifiChip HIDL APIs for coex

Add HIDL APIs to convey a list of unsafe Wifi channels to the driver for
coex channel avoidance.

Bug: 153651001
Test: build
Change-Id: I8b14f0e2d8855c1f1e363d612617256d8e928f30
diff --git a/wifi/1.5/default/wifi_legacy_hal.h b/wifi/1.5/default/wifi_legacy_hal.h
index 555c540..6266cf6 100644
--- a/wifi/1.5/default/wifi_legacy_hal.h
+++ b/wifi/1.5/default/wifi_legacy_hal.h
@@ -386,6 +386,11 @@
     virtual wifi_error multiStaSetPrimaryConnection(const std::string& ifname);
     virtual wifi_error multiStaSetUseCase(wifi_multi_sta_use_case use_case);
 
+    // Coex functions.
+    virtual wifi_error setCoexUnsafeChannels(
+        std::vector<wifi_coex_unsafe_channel> unsafe_channels,
+        uint32_t restrictions);
+
    private:
     // Retrieve interface handles for all the available interfaces.
     wifi_error retrieveIfaceHandles();