[2/2] cm: set cache partition location

* In init.rc, this prop will be used to set DOWNLOAD_CACHE
* If a device specifies having a dedicated /cache partition, by setting
  BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE, use it!
* Default to /data/cache per AOSP

Change-Id: I838672ca4638c9665333c1a67257fc435f33f388

config/BoardConfigCM.mk

@@ -2,3 +2,11 @@
 ifneq ($(WITH_CM_CHARGER),false)
     BOARD_HAL_STATIC_LIBRARIES := libhealthd.cm
 endif
+
+ifeq ($(BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE),)
+  ADDITIONAL_DEFAULT_PROPERTIES += \
+    ro.device.cache_dir=/data/cache
+else
+  ADDITIONAL_DEFAULT_PROPERTIES += \
+    ro.device.cache_dir=/cache
+endif