I9100G: recovery_keys: Add KEY_HOME

So apparently this was never added and the home button did nothing...

Change-Id: I85a575b31adbdce8e65d0c45e381dcbfb07a173e
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_device_samsung_i9100g into cd-4.4