msm: krait-l2-accessor: Add missing barriers

The Krait processor requires a barrier to be executed
between writing to L2CPUCPSELR and accessing L2CPUCPDR, to
ensure that the write to L2CPUCPSELR is reflected in the
access to L2CPUCPDR.

CRs-fixed: 367753
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
(cherry picked from commit 4d055616056994de077122c1a8c0a4370363c2ed)

Change-Id: I52a330455cb7c5d002d1d01ae6700c1347f9dc21
Signed-off-by: Srivalli Oguri <oguri@codeaurora.org>