msm8960: Fix rebooting from recovery

* I have no idea how this was previously working. It seems that the
   SEC_DEBUG stuff in the 3.0 kernel was someone magically making the
   bootloader do the right thing, but we were totally writing to the
   wrong partition. Oops!

Change-Id: I6e258210b2de60b98ba208210a93ce9a7c1fcbdb