plat-stm32mp1: scmi_server: report invalid regulator state request

Changes the SCMI return code from SCMI_GENERIC_ERROR to
SCMI_INVALID_PARAMETERS when the requested state is not one of
the 2 supported SCMI voltage domain states
(SCMI_VOLTAGE_DOMAIN_CONFIG_ARCH_ON or
SCMI_VOLTAGE_DOMAIN_CONFIG_ARCH_OFF).

Acked-by: Jerome Forissier <[email protected]>
Signed-off-by: Etienne Carriere <[email protected]>

core/arch/arm/plat-stm32mp1/scmi_server.c

@@ -893,7 +893,7 @@ int32_t plat_scmi_voltd_set_config(unsigned int channel_id,
 			}
 			break;
 		default:
-			return SCMI_GENERIC_ERROR;
+			return SCMI_INVALID_PARAMETERS;
 		}
 
 		return SCMI_SUCCESS;