Keep cscope.out when distclean.

It doesnt make sense to delete cscope.out when make
distclean. Distclean is done all the time, and cscope database is also
needed all the time. If we need to delete all the untracked files, we
can use git-clean.

Change-Id: Ic248ccd602ddc88d0b98d5d7f6cbbf530cd82e87
Signed-off-by: Zheng Bao <zheng.bao@amd.com>
Signed-off-by: zbao <fishbaozi@gmail.com>
Reviewed-on: http://review.coreboot.org/831
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
diff --git a/Makefile b/Makefile
index c5ee1f2..2723efb 100644
--- a/Makefile
+++ b/Makefile
@@ -276,7 +276,7 @@
 clean-cscope:
 	rm -f cscope.out
 
-distclean: clean-cscope
+distclean:
 	rm -rf $(obj)
 	rm -f .config .config.old ..config.tmp .kconfig.d .tmpconfig* .ccwrap .xcompile