firmware: arm_scpi: allow firmware with get_capabilities not implemented

On Amlogic SCPI legacy implementation, the GET_CAPABILITIES command is
not supported, failover by using 0.0.0 version.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
[sudeep.holla@arm.com: changed the subject]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
diff --git a/drivers/firmware/arm_scpi.c b/drivers/firmware/arm_scpi.c
index 2982bc7..9022336 100644
--- a/drivers/firmware/arm_scpi.c
+++ b/drivers/firmware/arm_scpi.c
@@ -783,6 +783,10 @@ static int scpi_init_versions(struct scpi_drvinfo *info)
 		info->protocol_version = le32_to_cpu(caps.protocol_version);
 		info->firmware_version = le32_to_cpu(caps.platform_version);
 	}
+	/* Ignore error if not implemented */
+	if (scpi_info->is_legacy && ret == -EOPNOTSUPP)
+		return 0;
+
 	return ret;
 }