package/batman-adv: needs linux kernel libcrc32c support

Fixes:

  ERROR: modpost: "crc32c" [.../build/batman-adv-2021.0/net/batman-adv/batman-adv.ko] undefined!

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 6754f656dede40d380f56086849fdd4092b15846)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/batman-adv/batman-adv.mk

@@ -34,5 +34,9 @@ define BATMAN_ADV_CONFIGURE_CMDS
 	$(BATMAN_ADV_MODULE_MAKE_OPTS) $(@D)/gen-compat-autoconf.sh $(@D)/compat-autoconf.h
 endef
 
+define BATMAN_ADV_LINUX_CONFIG_FIXUPS
+	$(call KCONFIG_ENABLE_OPT,CONFIG_LIBCRC32C)
+endef
+
 $(eval $(kernel-module))
 $(eval $(generic-package))