linux-module: Override dh_auto_clean

This avoids that fancy out-of-tree makefiles try their own cleaning
thing and fail in the build environment Debian provides. E.g.
https://github.com/google/gasket-driver/commit/b0049c17dc39e2511c6cc2f023751b709d66a6d4

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

meta/recipes-kernel/linux-module/files/debian/rules

@@ -24,6 +24,9 @@ ifneq (,$(findstring 86,$(DEB_HOST_GNU_CPU)))
 export ARCH=x86
 endif
 
+override_dh_auto_clean:
+	$(MAKE) -C $(KDIR) M=$(PWD) clean
+
 override_dh_auto_build:
 	$(MAKE) -C $(KDIR) M=$(PWD) modules