GPU: rename use-nvml to driver-specific

Because we are supporting drivers other than NVML

src/modules/gpu/option.h

@@ -18,6 +18,6 @@ typedef struct FFGPUOptions
 
     FFGPUType hideType;
     bool temp;
-    bool useNvml;
+    bool driverSpecific;
     bool forceVulkan;
 } FFGPUOptions;