firmware: xilinx: export the feature check of zynqmp firmware

Export the zynqmp_pm_feature(), so it can be use by other as to get API
version available in firmware.

Acked-by: Michal Simek <[e-mail]>
Signed-off-by: Rajan Vaja <[e-mail]>
Signed-off-by: Abhyuday Godhasara <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/firmware/xilinx/zynqmp.c

···
  *
  * Return: Returns status, either success or error+reason
  */
-static int zynqmp_pm_feature(u32 api_id)
+int zynqmp_pm_feature(const u32 api_id)
 {
 	int ret;
 	u32 ret_payload[PAYLOAD_ARG_CNT];
···
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(zynqmp_pm_feature);
 
 /**
  * zynqmp_pm_invoke_fn() - Invoke the system-level platform management layer

include/linux/firmware/xlnx-zynqmp.h

···
 int zynqmp_pm_load_pdi(const u32 src, const u64 address);
 int zynqmp_pm_register_notifier(const u32 node, const u32 event,
 				const u32 wake, const u32 enable);
+int zynqmp_pm_feature(const u32 api_id);
 #else
 static inline int zynqmp_pm_get_api_version(u32 *version)
 {
···
 
 static inline int zynqmp_pm_register_notifier(const u32 node, const u32 event,
 					      const u32 wake, const u32 enable)
+{
+	return -ENODEV;
+}
+
+static inline int zynqmp_pm_feature(const u32 api_id)
 {
 	return -ENODEV;
 }