Problem building app when ARCH=ppc

[blueskyjb at verizon.net]

This is a follow-up to my earlier post about
include/asm-ppc.

I've got a simple test case that won't build with
ELDK 4.1 configured for a ppc arch:

#include <signal.h>
main(int argc, char **argv)
{
   printf("hello world\n");
}

This build just fine with ELDK 4.0 using:

% ppc_6xx-gcc hello_world.c

In ELDK 4.1 it gets an error: asm/sigcontext.h: No such file or directory.  

Is include/asm-ppc broken
or do I need to add some additional compile option?

Thanks,

-- Jimmy