lib: crc: add `crc8_rohc` for CRC-8/ROHC variant calculation

This commit introduces the `crc8_rohc` function to the CRC library,
implementing the CRC-8/ROHC (RObust Header Compression) variant.
This algorithm is widely used in networking protocols, which is commonly
found in modem subsystems.

Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>