PATCH for SMTC: Update CP0 access macros

Commit ae462c65c5bad2d815cf3f0f3de36ee5187c72d8 changed the return value semantics of some macros in their base versions, but not in the SMTC variants. The attached patch fixes this.

Regards,

Kevin K.

Thanks to the Dead Supercomputer Society for fixing SMTC ;-)

Ralf