lib/Kconfig.debug: make CONFIG_STRICT_DEVMEM depend on CONFIG_DEVMEM

lib/Kconfig.debug: make CONFIG_STRICT_DEVMEM depend on CONFIG_DEVMEM

With CONFIG_DEVMEM not set, CONFIG_STRICT_DEVMEM will be useless even if
it is set =y, thus let's update the dependency in Kconfig.

Link: http://lkml.kernel.org/r/20161006051217.GA31027@dhcp-128-65.nay.redhat.com
Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>