Eliminates the link to arch specific asm-offsets.c from CRIS
architecture build system.

Resulting asm-offsets.s are identical before and after change
for both arch-v10 and arch-v32.
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>