2.6.1-mm2: Adjust MAX_MP_BUSSES for summit and generic subarches

Summit has it's own mach_mpspec.h, so it won't even see the summit changes you're proposing in mach-default:

+++ q1mm2/include/asm-i386/mach-generic/mach_mpspec.h 2004-01-13
[...]
+#if defined(CONFIG_X86_SUMMIT) || defined(CONFIG_X86_GENERICARCH)

Putting summit specific pieces in the subarch default is the wrong way to do it (and for this patch, it's even unnecessary since you modify the summit mach_mpspec.h anyway).

James