cris: cpuinfo_op should depend on CONFIG_PROC_FS

Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
disable options behind EMBEDDED and EXPERT".

Now allnoconfig started disabling CONFIG_PROC_FS:

    arch/cris/kernel/built-in.o:(.rodata+0xc): undefined reference to `show_cpuinfo'
    make: *** [vmlinux] Error 1

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>