Fix subvendor_id error handling

Change-Id: Ibb2e8e329233221e72247674b4f2fbaef51baa32
Signed-off-by: Maisam Arif <maisarif@amd.com>

py-interface/amdsmi_interface.py

@@ -1557,7 +1557,7 @@ def amdsmi_get_gpu_asic_info(
         "market_name": asic_info.market_name.decode("utf-8"),
         "vendor_id": asic_info.vendor_id,
         "vendor_name": asic_info.vendor_name.decode("utf-8"),
-        "subvendor_id": hex(asic_info.subvendor_id),
+        "subvendor_id": asic_info.subvendor_id if asic_info.subvendor_id == '' else hex(asic_info.subvendor_id),
         "device_id": asic_info.device_id,
         "rev_id": asic_info.rev_id,
         "asic_serial": asic_info.asic_serial.decode("utf-8"),