Allow to build against Mac OS X SDK 10.11.

Bug: 24739158
Change-Id: I7c57e141dd02a0d2de5a7a1ccbc72ffe422a8d6f
diff --git a/core/combo/mac_version.mk b/core/combo/mac_version.mk
index 638e3a0..f6bd852 100644
--- a/core/combo/mac_version.mk
+++ b/core/combo/mac_version.mk
@@ -9,7 +9,7 @@
 
 build_mac_version := $(shell sw_vers -productVersion)
 
-mac_sdk_versions_supported :=  10.8 10.9 10.10
+mac_sdk_versions_supported :=  10.8 10.9 10.10 10.11
 ifneq ($(strip $(MAC_SDK_VERSION)),)
 mac_sdk_version := $(MAC_SDK_VERSION)
 ifeq ($(filter $(mac_sdk_version),$(mac_sdk_versions_supported)),)