hostapd: fix build error on some variants with CONFIG_WPA_RFKILL_SUPPORT=y (#17765)

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@43345 3c298f89-4303-0410-b956-a3cf2f4a3e73