[PATCH v2] Kbuild: enable -Wunused-macros warning for "make W=2"

[Johannes Thumshirn]

We have lots of dead defines and macros in drivers, lets offer users a way
to detect and eventually remove them.

Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
---

Notes:
    Changes to v1:
    * Change from W=1 to W=2

 scripts/Makefile.extrawarn | 1 +
 1 file changed, 1 insertion(+)

diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index fb3522fd8702..ae8a1357d01d 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -37,6 +37,7 @@ warning-2 += $(call cc-option, -Wlogical-op)
 warning-2 += $(call cc-option, -Wmissing-field-initializers)
 warning-2 += $(call cc-option, -Wsign-compare)
 warning-2 += $(call cc-option, -Wmaybe-uninitialized)
+warning-2 += $(call cc-option, -Wunused-macros)
 
 warning-3 := -Wbad-function-cast
 warning-3 += -Wcast-qual
-- 
2.12.3