kbuild: remove Module.markers during mrproper

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Makefile

diff --git a/Makefile b/Makefile
index 828c838..b4a52d2 100644
--- a/Makefile
+++ b/Makefile
@@ -1155,7 +1155,7 @@
                   include/linux/autoconf.h include/linux/version.h      \
                   include/linux/utsrelease.h                            \
                   include/linux/bounds.h include/asm*/asm-offsets.h     \
-		  Module.symvers tags TAGS cscope*
+		  Module.symvers Module.markers tags TAGS cscope*
 
 # clean - Delete most, but leave enough to build external modules
 #