There is no point in freeing HYP page tables differently from Stage-2.
They now have the same requirements, and should be dealt with the same way.

Promote unmap_stage2_range to be The One True Way, and get rid of a number
of nasty bugs in the process (good thing we never actually called free_hyp_pmds
before...).
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <cdall@cs.columbia.edu>