Add support for per device bluetooth configuration.

Bug: 6837125
Change-Id: Id8bcf088235f3650574d08ec592d10a6706b4960

BoardConfig.mk

diff --git a/BoardConfig.mk b/BoardConfig.mk
index dd90262..c07098f 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -18,6 +18,7 @@
 MINIMAL_FONT_FOOTPRINT := true
 # Some framework code requires this to enable BT
 BOARD_HAVE_BLUETOOTH := true
+BOARD_BLUETOOTH_BDROID_BUILDCFG_INCLUDE_DIR := device/generic/common/bluetooth
 
 WPA_SUPPLICANT_VERSION := VER_0_8_X