releasetools: Don't delete the device specific files

They are needed for extract-files to work

Change-Id: I8d5d69c20f487708c519b2e1b8dbf8f4bfa43229
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_device_motorola_moto_msm8960dt into cd-4.4
Build charger and stop using a prebuilt charge_only_mode

Change-Id: I7fe90998a5cd0312c0a031d197df92ceee28c6f4
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_device_motorola_moto_msm8960dt into cd-4.4