selftests: powerpc: override clean in lib.mk to fix warnings

Add override for lib.mk clean to fix the following warnings from clean
target run.

Makefile:63: warning: overriding recipe for target 'clean'
../lib.mk:55: warning: ignoring old recipe for target 'clean'

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile
index 1c5d0575802e..8d9fc64c8761 100644
--- a/tools/testing/selftests/powerpc/Makefile
+++ b/tools/testing/selftests/powerpc/Makefile
@@ -59,12 +59,13 @@ override define EMIT_TESTS
         done;
 endef
 
-clean:
+override define CLEAN
         @for TARGET in $(SUB_DIRS); do \
                 BUILD_TARGET=$$OUTPUT/$$TARGET; \
                 $(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET clean; \
         done;
         rm -f tags
+endef
 
 tags:
         find . -name '*.c' -o -name '*.h' | xargs ctags