power: regulator: qcom-rpmh: read votes from rpmh

power: regulator: qcom-rpmh: read votes from rpmh

Make use of the new RPMh read support to fetch regulator values that may
have been voted on by a previous bootloader stage. This allows commands
like "regulator status" to report the actual votes programmed into
hardware (though not necessarily the actual states of the regulators
once the votes have been aggregated).

Link: https://patch.msgid.link/20260108-rpmh-regulator-fixes-v1-5-d1b5b300b665@linaro.org
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>