add external/google, exfat, ntfs-3g

These additions accompany these 2 commits in vendor/cm:
https://github.com/BeerGang/android_vendor_cm/commit/90f964168acb40886282761243a5fd91f29ab154
https://github.com/BeerGang/android_vendor_cm/commit/c841b4bd1e1e857c86380bc6c1e433705ee38520