recovery: Add a proper CleanSpec.mk

 * Clean all the stuff that conflicts with AOSP recovery.

Change-Id: I175329c446a014c451f4c0fc5a9a4472941afc10
recovery: Clean ALL the things

 * We need to clean everything, otherwise nasty things happen when
   switching to alternate recovery module.

Change-Id: I9ea88179f5329112c587b649328c1c83df0bd5d9