msm: Kconfig: select MSM_SPM_REGULATOR for msmsamarium

Select the MSM_SPM_REGULATOR config option for msmsamarium so
that the processor supply regulators may be controlled via the
spm-regulator driver.

Change-Id: Iebc0ab9cb1cf94c2c4dd93ea90ae1c6ce3b524e4
Signed-off-by: David Collins <collinsd@codeaurora.org>