firmware: scmi: use scmi_proto_driver_get() function to get SCMI protocol driver

If there is a SoC specific SCMI protocol driver, using
scmi_proto_driver_get() function can avoid to add SoC specific code to
scmi_agent-uclass.c.

Signed-off-by: Alice Guo <alice.guo@nxp.com>
diff --git a/drivers/firmware/scmi/scmi_agent-uclass.c b/drivers/firmware/scmi/scmi_agent-uclass.c
index ea79cfa..cc3f31d 100644
--- a/drivers/firmware/scmi/scmi_agent-uclass.c
+++ b/drivers/firmware/scmi/scmi_agent-uclass.c
@@ -425,31 +425,11 @@
 
 		drv = NULL;
 		name = ofnode_get_name(node);
-		switch (protocol_id) {
-		case SCMI_PROTOCOL_ID_POWER_DOMAIN:
-			if (CONFIG_IS_ENABLED(SCMI_POWER_DOMAIN) &&
-			    scmi_protocol_is_supported(dev, protocol_id))
-				drv = DM_DRIVER_GET(scmi_power_domain);
-			break;
-		case SCMI_PROTOCOL_ID_CLOCK:
-			if (CONFIG_IS_ENABLED(CLK_SCMI) &&
-			    scmi_protocol_is_supported(dev, protocol_id))
-				drv = DM_DRIVER_GET(scmi_clock);
-			break;
-		case SCMI_PROTOCOL_ID_RESET_DOMAIN:
-			if (IS_ENABLED(CONFIG_RESET_SCMI) &&
-			    scmi_protocol_is_supported(dev, protocol_id))
-				drv = DM_DRIVER_GET(scmi_reset_domain);
-			break;
-		case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
-			if (IS_ENABLED(CONFIG_DM_REGULATOR_SCMI) &&
-			    scmi_protocol_is_supported(dev, protocol_id))
-				drv = DM_DRIVER_GET(scmi_voltage_domain);
-			break;
-		default:
-			break;
-		}
+
+		if (!scmi_protocol_is_supported(dev, protocol_id))
+			continue;
 
+		drv = scmi_proto_driver_get(protocol_id);
 		if (!drv) {
 			dev_dbg(dev, "Ignore unsupported SCMI protocol %#x\n",
 				protocol_id);