[GPU] Added janky(?) support for register: D1MODE_V_COUNTER

Put internal_display_resolution into graphics_system

Thanks Beeanyew for initial implementation

src/xenia/cpu/testing/premake5.lua

@@ -9,6 +9,7 @@ test_suite("xenia-cpu-tests", project_root, ".", {
     "xenia-base",
     "xenia-core",
     "xenia-cpu",
+    "xenia-gpu",
 
     -- TODO(benvanik): cut these dependencies?
     "xenia-kernel",