BoardConfigQcom: Allow a device to opt-out hardset of PRODUCT_SOONG_NAMESPACES

By setting QCOM_SOONG_NAMESPACE in device.mk
This will allow a device to specify a device specific branch within
hardware/qcom-caf/ or the device tree.

Signed-off-by: Andrew Hexen <SyberHexen@gmail.com>
Change-Id: I39693a0fb9665129f0810590d389c4cb06cdf8d7
diff --git a/config/BoardConfigQcom.mk b/config/BoardConfigQcom.mk
index bd143ba..9657e6b 100644
--- a/config/BoardConfigQcom.mk
+++ b/config/BoardConfigQcom.mk
@@ -86,5 +86,6 @@
     QCOM_HARDWARE_VARIANT := $(TARGET_BOARD_PLATFORM)
 endif
 
-PRODUCT_SOONG_NAMESPACES += \
-    hardware/qcom-caf/$(QCOM_HARDWARE_VARIANT)
+# Allow a device to opt-out hardset of PRODUCT_SOONG_NAMESPACES
+QCOM_SOONG_NAMESPACE ?= hardware/qcom-caf/$(QCOM_HARDWARE_VARIANT)
+PRODUCT_SOONG_NAMESPACES += $(QCOM_SOONG_NAMESPACE)