remoteproc: q6v5-mss: Active powerdomain for SDM845

The SDM845 MSS needs the load_state powerdomain voted for during the
duration of the MSS being powered on, to let the AOSS know that it may
not perform certain power save measures. So vote for this.

Tested-by: Sibi Sankar <sibis@codeaurora.org>
Reviewed-by: Sibi Sankar <sibis@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>