Some work on the Voodoo emulation
- destructor: free memory only when initialized
- parameter 'enabled' must be initialized with 1 (TODO: fix other plugins)
- PCI register fixes (Voodoo2 now detected, but not usable)


git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@12084 6c8e4198-a580-4521-a02f-c9ae86df1db9