fix build regression in sh-nofpu subarch due to missing symbol

commit 646cb9a4 switched sigsetjmp to
use the new hidden ___setjmp symbol for setjmp, but the nofpu variant
of setjmp.s was not updated to match.

src/setjmp/sh-nofpu/setjmp.s

+.global ___setjmp
+.hidden ___setjmp
 .global __setjmp
 .global _setjmp
 .global setjmp
 .type   __setjmp, @function
 .type   _setjmp,  @function
 .type   setjmp,   @function
+___setjmp:
 __setjmp:
 _setjmp:
 setjmp: