Drop BOARD_SEPOLICY_UNION.

As suggested in the comments on
https://android-review.googlesource.com/#/c/141560/
drop BOARD_SEPOLICY_UNION and simplify the build_policy logic.
Union all files found under BOARD_SEPOLICY_DIRS.

Change-Id: I4214893c999c23631f5456cb1b8edd59771ef13b
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
diff --git a/BoardConfig.mk b/BoardConfig.mk
index f4354f4..0744d72 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -103,41 +103,7 @@
 
 BOARD_HAL_STATIC_LIBRARIES := libdumpstate.hammerhead
 
-BOARD_SEPOLICY_DIRS += \
-       device/lge/hammerhead/sepolicy
-
-BOARD_SEPOLICY_UNION += \
-       app.te \
-       bluetooth_loader.te \
-       bridge.te \
-       camera.te \
-       device.te \
-       domain.te \
-       file.te \
-       hostapd.te \
-       init.te \
-       irsc_util.te \
-       mediaserver.te \
-       mpdecision.te \
-       netmgrd.te \
-       platform_app.te \
-       qmux.te \
-       radio.te \
-       rild.te \
-       rmt.te \
-       sensors.te \
-       ssr.te \
-       surfaceflinger.te \
-       system_server.te \
-       tee.te \
-       thermald.te \
-       time.te \
-       ueventd.te \
-       vss.te \
-       wpa.te \
-       file_contexts \
-       genfs_contexts \
-       te_macros
+BOARD_SEPOLICY_DIRS += device/lge/hammerhead/sepolicy
 
 HAVE_ADRENO_SOURCE:= false