msm: Kconfig: select MSM_RPM_REGULATOR_SMD on msmkrypton

Enable the configuration option for the rpm-regulator-smd driver so that
consumers can make requests for RPM controlled regulators.

Change-Id: If9c834c6199f3c5eb5f5fe90637ed936fe0d131e
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>