U-Boot CRC-16 implementation uses polynomial x^16 + x^12 + x^5 + 1 which is
not standard CRC-16 algorithm, but it is known as CRC-16-CCITT. Rename file
crc16.c to crc16-ccitt.c to reduce confusion.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>