remoteproc: qcom_q6v5_pas: Make single-PD handling more robust

Only go into the if condition for single-PD handling when there's
actually just one power domain specified there. Otherwise it'll be an
issue in the dts and we should fail in the regular code path.

This also mirrors the latest changes in the qcom_q6v5_mss driver.

Suggested-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Fixes: 17ee2fb ("remoteproc: qcom: pas: Vote for active/proxy power domains")
Signed-off-by: Luca Weiss <luca@lucaweiss.eu>
Reviewed-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Link: https://lore.kernel.org/r/20250128-pas-singlepd-v1-2-85d9ae4b0093@lucaweiss.eu
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Author: z3ntu

drivers/remoteproc/qcom_q6v5_pas.c

@@ -501,16 +501,16 @@ static int adsp_pds_attach(struct device *dev, struct device **devs,
 	if (!pd_names)
 		return 0;
 
+	while (pd_names[num_pds])
+		num_pds++;
+
 	/* Handle single power domain */
-	if (dev->pm_domain) {
+	if (num_pds == 1 && dev->pm_domain) {
 		devs[0] = dev;
 		pm_runtime_enable(dev);
 		return 1;
 	}
 
-	while (pd_names[num_pds])
-		num_pds++;
-
 	for (i = 0; i < num_pds; i++) {
 		devs[i] = dev_pm_domain_attach_by_name(dev, pd_names[i]);
 		if (IS_ERR_OR_NULL(devs[i])) {
@@ -535,7 +535,7 @@ static void adsp_pds_detach(struct qcom_adsp *adsp, struct device **pds,
 	int i;
 
 	/* Handle single power domain */
-	if (dev->pm_domain && pd_count) {
+	if (pd_count == 1 && dev->pm_domain) {
 		pm_runtime_disable(dev);
 		return;
 	}