nvidia-settings: fix parallel build race condition

Fix a race condition that occurs in parallel builds of
nvidia-settings, frequently ending in the following error:

/bin/bash: _out/Linux_x86_64/antialias.png.h: No such file or directory
make[1]: *** [Makefile:320: _out/Linux_x86_64/antialias.png.h] Error 1

Upstream issue and fix from:
https://github.com/NVIDIA/nvidia-settings/issues/59

pkgs/os-specific/linux/nvidia-x11/nvidia-setttings-parallel-build.patch

@@ -0,0 +1,12 @@
+diff --git a/src/Makefile b/src/Makefile
+index acbb1b8..fe97103 100644
+--- a/src/Makefile
++++ b/src/Makefile
+@@ -242,6 +242,7 @@ endif
+ 
+ define BINARY_DATA_HEADER_RULE
+   $$(OUTPUTDIR)/$(notdir $(1)).h:
++	$(at_if_quiet)$(MKDIR) $$(OUTPUTDIR)
+ 	$(at_if_quiet){ \
+ 	  $$(PRINTF) "extern const char _binary_$(subst .,_,$(notdir $(1)))_start[];\n"; \
+ 	  $$(PRINTF) "extern const char _binary_$(subst .,_,$(notdir $(1)))_end[];\n"; \

pkgs/os-specific/linux/nvidia-x11/settings.nix

@@ -45,6 +45,12 @@ stdenv.mkDerivation {
   version = nvidia_x11.settingsVersion;
   inherit src;
 
+  patches = [
+    # Fix a race condition in parallel builds.
+    # https://github.com/NVIDIA/nvidia-settings/issues/59#issuecomment-770302032
+    ./nvidia-setttings-parallel-build.patch
+  ];
+
   nativeBuildInputs = [ pkg-config m4 ];
 
   buildInputs = [ jansson libXv libXrandr libXext libXxf86vm libvdpau nvidia_x11 gtk2 dbus ]