m68k: Convert missed RODATA to RO_DATA

I missed two instances of the old RODATA macro (seems I was searching
for vmlinux.lds* not vmlinux*lds*). Fix both instances and double-check
the entire tree for other "RODATA" instances in linker scripts.

Fixes: c8231825

 ("vmlinux.lds.h: Replace RODATA with RO_DATA")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-m68k@lists.linux-m68k.org
Cc: Sam Creasey <sammy@sammy.net>
Link: https://lkml.kernel.org/r/201911110920.5840E9AF1@keescook