Setup common tuna extract-files/remove Google self-extractors

Since tuna devices are no longer maintained by AOSP there is
no need to have multiple locations and duplicate files. This
Will put all common files in vendor/samsung/tuna and device
specific ones in vendor/samsung/maguro.

Change-Id: If4fc5688c82da031993b49a6f74807f31df21a1d

Conflicts:
	device.mk
	self-extractors/generate-packages.sh