2.4.22-ben2 : - Remove a hack on the MachineCheck exception handler that seemed
                to actually cause a problem on some machines
              - Turn legacy serial driver into a module (used by pcmcia modems)
	        instead of built-in in pmac defconfig
              - Export a couple of symbols needed by recent DRI
              - Hopefully close a few possible SMP races along with making the
	        IO ops more robust vs. store reordering.
              - Fix build without CONFIG_PMAC_PBOOK

2.4.22-ben1 : First release