Uhm, oh, now i get it, I know what you mean now. Maybe there is no easy way if the kernel is not for the corresponding arch...
But maybe you could use "cpuid" program to get the output for the processor type
cpuid - Intel and AMD x86 CPUID display program
As I told you, I have x86 Ubuntu, but my processor is x86_64.
dan@alcon:~$ cpuid | grep Processor
Processor name string: AMD Athlon(tm) 64 Processor 3000+
Maybe you can check this also:
libsys-cpu-perl - Sys::CPU Perl module for getting CPU information