msm8953-common: Clear the recovery cache in persist on boot

* Due to the way newer TWRP versions are behaving, our relatively small
  persist partition gets overfilled with recovery logs very quickly.
* Let's just remove the recovery cache from persist on every boot to be sure
  that we always have enough space for anything that writes to persist.

Change-Id: Id1502dfb5e504504601a21efb7812b84a7155e58