p1: twrp: change the order of mounts

this patch changes the order of mounts by updating
[twrp.]fstab[.p1]
the main reason of this is for new installing process that
requires a soft wipe: cache, dalvik and/or system

so, these mounts will be grouped at top of 3 positions
of wipe list.

Signed-off-by: Humberto Borba <humberos@gmail.com>
Change-Id: I43bf21773502d2285082ec19bf3816ecb2bfb876