Remove framerate restrictions

If game devs want to use framerates outside of Enterbrain's arbitrary
restrictions, there's no reason for us to prevent it. Same reason we
don't restrict the resolution.

Fixes mkxp-z#64

src/display/graphics.cpp

@@ -1358,7 +1358,7 @@ DEF_ATTR_RD_SIMPLE(Graphics, FrameRate, int, p->frameRate)
 DEF_ATTR_SIMPLE(Graphics, FrameCount, int, p->frameCount)
 
 void Graphics::setFrameRate(int value) {
-    p->frameRate = clamp(value, 10, 120);
+    p->frameRate = std::max(value, 1);
 
     if (p->threadData->config.syncToRefreshrate)
         return;