Removed unused define.
TODO: improve virtual timer to make operate in both modes at the same time.
The vga update code should always use the realtime mode and the pit timing
should depend on the clock option.


git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@12500 6c8e4198-a580-4521-a02f-c9ae86df1db9