mfd: msm_rpm: Correct rpm version

Update the expected version of the rpm after testing things.

Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
regulators: msm_rpm: Add get_voltage so set_voltage doesn't fail

Calling set_voltage on a regulator that doesn't allow setting voltage fails
unless the proposed voltage spans the current voltage. So implement get_voltage
so that the check have a chance to pass.

Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
regulator: msm_rpm: Add pm8921_l17 and pm8921_l29

Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>