hmd2: initialize a virtual headset with --vr

Inspired by https://github.com/KytyPS5/KytyPS5/pull/607

Co-authored-by: BlackCAT <52720489+psnwd@users.noreply.github.com>

src/common/emulatorConfig.cpp

@@ -55,6 +55,10 @@ bool FullscreenEnabled() {
 	return g_config->fullscreen_enabled;
 }
 
+bool VrEnabled() {
+	return g_config->vr_enabled;
+}
+
 uint32_t GetVblankFrequency() {
 	return std::clamp(g_config->vblank_frequency, 30u, 360u);
 }