Parallel flash bugfixes:

- always need to register flash area back to IO_MEM_ROMD at reset time
- disabled buffered write as it's not actually supported
- don't check flash time at registration time


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2678 c046a42c-6fe2-441c-8c8c-71466251a162