staging/wlan-ng: add CRC32 dependency in Kconfig

wlan-ng uses the function crc32_le,
but CRC32 wasn't a dependency of wlan-ng

Co-developed-by: Michael Kupfer <michael.kupfer@fau.de>
Signed-off-by: Michael Kupfer <michael.kupfer@fau.de>
Signed-off-by: Kay Friedrich <kay.friedrich@fau.de>
Link: https://lore.kernel.org/r/20191127112457.2301-1-kay.friedrich@fau.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>