ARM: dts: msm: Add RPM regulator for S2 on apq8084

Add rpm-regulator-smd corner device for PMA8084 regulator
S2 on APQ8084 target to allow device consumers to vote for
both active and sleep set on this resource.

Change-Id: Iacd2b01e42a1d01c3378337881ac5a0e6c5f6ec2
Signed-off-by: Tianyi Gou <tgou@codeaurora.org>