ARM: dts: msm: Update rpm-stats unit addr for Kona

The RPM stats driver accesses the RPMH msgram based off the data in the
offset addr. Update the node unit address to reflect this and to
prevent unit address collision with the QMP node.

Change-Id: I3a09255cf1a5ecbfaefff162a88e1aba7962c9f4
Signed-off-by: Chris Lew <clew@codeaurora.org>