msm: krait-l2-accessors: Remove workaround for 8064 Krait errata

This workaround can be removed in favor of an alternate solution
implemented in the power-collapse path which backs up the
corruptable L2CPUCPMR and L2CPMR registers before L2 power-collase
and restores them afterwards.

CRs-Fixed: 400700
Change-Id: I8bfa87fa9c163cecb712e18ed64151e9bbde4cc3
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>