config: Don't include cmsdk_common if cm sdk is disabled

Change-Id: Ie5ef054213c5804352ae0e076d515b1de9e11396
diff --git a/config/common.mk b/config/common.mk
index 9e788a9..f85f47d 100644
--- a/config/common.mk
+++ b/config/common.mk
@@ -126,8 +126,10 @@
 # Theme engine
 include vendor/cm/config/themes_common.mk
 
+ifneq ($(TARGET_DISABLE_CMSDK), true)
 # CMSDK
 include vendor/cm/config/cmsdk_common.mk
+endif
 
 # Required CM packages
 PRODUCT_PACKAGES += \