remoteproc: qcom_q6v5_pas: Do not fail if regulators are not found

devm_regulator_get_optional() API will return -ENODEV if the regulator was
not found. For the optional supplies CX, PX we should not fail in that case
but rather continue. So let's catch that error and continue silently if
those regulators are not found.

The commit 3f52d11 ("remoteproc: qcom_q6v5_pas: Deal silently with
optional px and cx regulators") was supposed to do the same but it missed
the fact that devm_regulator_get_optional() API returns -ENODEV when the
regulator was not found.

Cc: Abel Vesa <abel.vesa@linaro.org>
Fixes: 3f52d11 ("remoteproc: qcom_q6v5_pas: Deal silently with optional px and cx regulators")
Reported-by: Steev Klimaszewski <steev@kali.org>
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Steev Klimaszewski <steev@kali.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220801053939.12556-1-manivannan.sadhasivam@linaro.org

drivers/remoteproc/qcom_q6v5_pas.c

@@ -362,13 +362,25 @@ static int adsp_init_clock(struct qcom_adsp *adsp)
 static int adsp_init_regulator(struct qcom_adsp *adsp)
 {
 	adsp->cx_supply = devm_regulator_get_optional(adsp->dev, "cx");
-	if (IS_ERR(adsp->cx_supply))
-		return PTR_ERR(adsp->cx_supply);
+	if (IS_ERR(adsp->cx_supply)) {
+		if (PTR_ERR(adsp->cx_supply) == -ENODEV)
+			adsp->cx_supply = NULL;
+		else
+			return PTR_ERR(adsp->cx_supply);
+	}
 
-	regulator_set_load(adsp->cx_supply, 100000);
+	if (adsp->cx_supply)
+		regulator_set_load(adsp->cx_supply, 100000);
 
 	adsp->px_supply = devm_regulator_get_optional(adsp->dev, "px");
-	return PTR_ERR_OR_ZERO(adsp->px_supply);
+	if (IS_ERR(adsp->px_supply)) {
+		if (PTR_ERR(adsp->px_supply) == -ENODEV)
+			adsp->px_supply = NULL;
+		else
+			return PTR_ERR(adsp->px_supply);
+	}
+
+	return 0;
 }
 
 static int adsp_pds_attach(struct device *dev, struct device **devs,