hostap: Replace menuconfig by config

This avoid compliance warning

Found pointless 'menuconfig' symbols without children. Use regular 'config'
symbols instead. See
https://docs.zephyrproject.org/latest/build/kconfig/tips.html#menuconfig-symbols

.

WIFI_NM_WPA_SUPPLICANT              modules/hostap/Kconfig:8
WIFI_NM_WPA_SUPPLICANT              modules/hostap/Kconfig:8

Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>