Merge pull request #13548 from aliaspider/libretro-fixes

Libretro: add SYSPROP_DISPLAY_SAFE_INSET* properties. fixes screen size.

libretro/libretro.cpp

@@ -888,6 +888,11 @@ float System_GetPropertyFloat(SystemProperty prop)
    {
       case SYSPROP_DISPLAY_REFRESH_RATE:
          return 60.f;
+      case SYSPROP_DISPLAY_SAFE_INSET_LEFT:
+      case SYSPROP_DISPLAY_SAFE_INSET_RIGHT:
+      case SYSPROP_DISPLAY_SAFE_INSET_TOP:
+      case SYSPROP_DISPLAY_SAFE_INSET_BOTTOM:
+         return 0.0f;
       default:
          break;
    }