qcacld-3.0: Update hardcoded path for BOARD_OPENSOURCE_DIR

Some targets use a different location for the build scripts and
set the BOARD_OPENSOURCE_DIR build variable accordingly.
If this variable is set, pick up WLAN source code from this location.

Change-Id: I3ff09ac25ab6ce627f658182b395371de1a1969e
CRs-Fixed: 3636187

Android.mk

@@ -32,6 +32,7 @@ endif
 
 LOCAL_PATH := $(call my-dir)
 $(call wlog,LOCAL_PATH=$(LOCAL_PATH))
+BOARD_OPENSOURCE_DIR ?= vendor/qcom/opensource
 
 ENABLE_QCACLD := true
 ifeq ($(TARGET_USES_QMAA), true)
@@ -66,7 +67,7 @@ ifneq ($(WLAN_CHIPSET),)
 ifneq ($(findstring vendor,$(LOCAL_PATH)),)
 
 ifneq ($(findstring opensource,$(LOCAL_PATH)),)
-	WLAN_BLD_DIR := vendor/qcom/opensource/wlan
+	WLAN_BLD_DIR := $(BOARD_OPENSOURCE_DIR)/wlan
 endif # opensource
 
 # Multi-ko check