libobs/graphics: Add gs_is_monitor_hdr

Only Windows is implemented for now. Mac/Linux return false for now.

libobs-opengl/gl-cocoa.m

@@ -310,6 +310,11 @@ void device_present(gs_device_t *device)
 	[device->plat->context makeCurrentContext];
 }
 
+bool device_is_monitor_hdr(gs_device_t *device, void *monitor)
+{
+	return false;
+}
+
 void gl_getclientsize(const struct gs_swap_chain *swap, uint32_t *width,
 		      uint32_t *height)
 {

libobs-opengl/gl-nix.c

@@ -124,6 +124,11 @@ extern void device_present(gs_device_t *device)
 	gl_vtable->device_present(device);
 }
 
+extern bool device_is_monitor_hdr(gs_device_t *device, void *monitor)
+{
+	return false;
+}
+
 extern struct gs_texture *device_texture_create_from_dmabuf(
 	gs_device_t *device, unsigned int width, unsigned int height,
 	uint32_t drm_format, enum gs_color_format color_format,

libobs-opengl/gl-windows.c

@@ -598,6 +598,11 @@ extern void gl_getclientsize(const struct gs_swap_chain *swap, uint32_t *width,
 	}
 }
 
+EXPORT bool device_is_monitor_hdr(gs_device_t *device, void *monitor)
+{
+	return false;
+}
+
 EXPORT bool device_gdi_texture_available(void)
 {
 	return false;