axolotl-shiftos: disable mainline modules

Currently the tethering apex ships without support for kernel 4.9.
Starting with aml_tet_331117000 this support is restored.

Change-Id: I13c9957068e70e1906455fc3f1fb8c08c48814a2
Signed-off-by: Alexander Martinz <amartinz@shiftphones.com>
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 9751f26..3bd61f5 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -6,11 +6,11 @@
 
 ### AVB
 
-ifeq ($(WITH_GMS_MAINLINE),true)
-    PRIVATE_KEY_PATH := vendor/shiftos/private/keys/mainline/avb-4096.pem
-else
+#ifeq ($(WITH_GMS_MAINLINE),true)
+#    PRIVATE_KEY_PATH := vendor/shiftos/private/keys/mainline/avb-4096.pem
+#else
     PRIVATE_KEY_PATH := vendor/shiftos/private/keys/stock/avb-4096.pem
-endif
+#endif
 
 # If private key does not exist, fallback to testkey
 ifeq ($(wildcard $(PRIVATE_KEY_PATH)),)