qcacld-3.0: Add support for Build_external_kernelmodule.mk

The Android build infrastructure is transitioning to a new
mechansim for building external modules. Update the qcacld-3.0
driver to use that mechanism for toro builds.

Change-Id: I7d73bc1ccbde5ecc74c661fd6e31525b266413cd
CRs-Fixed: 2852877

Android.mk

@@ -155,7 +155,11 @@ else
     LOCAL_MODULE_PATH := $(TARGET_OUT)/lib/modules/$(WLAN_CHIPSET)
 endif
 
-include $(DLKM_DIR)/AndroidKernelModule.mk
+ifeq ($(TARGET_PRODUCT), taro)
+    include $(DLKM_DIR)/Build_external_kernelmodule.mk
+else
+    include $(DLKM_DIR)/AndroidKernelModule.mk
+endif
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