stack protector: create HAVE_CC_STACKPROTECTOR for centralized use

stack protector: create HAVE_CC_STACKPROTECTOR for centralized use

Instead of duplicating the CC_STACKPROTECTOR Kconfig and Makefile logic in
each architecture, switch to using HAVE_CC_STACKPROTECTOR and keep
everything in one place.  This retains the x86-specific bug verification
scripts.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>