batman-adv: use CRC32C instead of CRC16 in TT code

CRC32C has to be preferred to CRC16 because of its possible
HW native support and because of the reduced collision
probability. With this change the Translation Table
component now uses CRC32C to compute the local and global
table checksum.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>