Don't build with nvml for non-nvidia

src/cpu_gpu.h

@@ -191,15 +191,17 @@ void *cpuInfo(void *){
 }
 
 void *getNvidiaGpuInfo(void *){
-	if (!nvmlSuccess)
-		checkNvidia();
-
-	if (nvmlSuccess){
-		getNvidiaInfo();	
-		gpuLoad = nvidiaUtilization.gpu;
-		gpuLoadDisplay = gpuLoad;
-		gpuTemp = nvidiaTemp;
-	}
+	#ifdef HAVE_NVML
+		if (!nvmlSuccess)
+			checkNvidia();
+
+		if (nvmlSuccess){
+			getNvidiaInfo();	
+			gpuLoad = nvidiaUtilization.gpu;
+			gpuLoadDisplay = gpuLoad;
+			gpuTemp = nvidiaTemp;
+		}
+	#endif
 	
 	pthread_detach(nvidiaSmiThread);
 	return NULL;

src/meson.build

@@ -35,10 +35,14 @@ vklayer_files = files(
   'overlay.cpp',
   'overlay_params.c',
   'font_unispace.c',
-  'nvml.c',
 )
 
-dep_nvml = cc.find_library('nvidia-ml')
+dep_nvml = cc.find_library('nvidia-ml', required: false)
+if dep_nvml.found()
+  vklayer_files += 'nvml.c'
+  pre_args += '-DHAVE_NVML'
+endif
+
 vklayer_mesa_overlay = shared_library(
   'MangoHud',
   util_files,