lib: add module support to atomic64 tests

Allow to compile the atomic64 test code either to a loadable module, or
builtin into the kernel.

Link: http://lkml.kernel.org/r/1483470276-10517-3-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 66fb438..213decb 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1790,9 +1790,10 @@
 	  If unsure, say N.
 
 config ATOMIC64_SELFTEST
-	bool "Perform an atomic64_t self-test at boot"
+	tristate "Perform an atomic64_t self-test"
 	help
-	  Enable this option to test the atomic64_t functions at boot.
+	  Enable this option to test the atomic64_t functions at boot or
+	  at module load time.
 
 	  If unsure, say N.