Call objclean target instead of using find command to do a build clean.
This ensures that all files created on-the-fly during the build
will be removed if correctly listed into the objclean-y target.

Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>

Index: Makefile.in
===================================================================
--- Makefile.in	(revision 21163)
+++ Makefile.in	(working copy)
@@ -343,8 +343,7 @@
 	$(Q)$(RM) -r lib include/bits
 	$(RM) lib*/*.a ldso/*/*.a libpthread/*/*.a
 	$(RM) include/fpu_control.h include/dl-osinfo.h include/hp-timing.h
-	$(MAKE) -C extra/locale locale_clean
-	$(MAKE) headers_clean-y
+	$(MAKE) objclean-y headers_clean-y
 	$(MAKE) -s -C test clean
 	$(MAKE) -C utils utils_clean
 	@set -e; \
@@ -357,7 +356,6 @@
 		done; \
 	fi
 	@$(RM) include/linux include/asm*
-	-find . \( -name \*.o -o -name \*.os -o -name \*.oS \) -exec $(RM) {} \;
 
 distclean: clean
 	-find . \( -name core -o -name \*.orig -o -name \*~ \) -exec $(RM) {} \;