ptp: ocp: Select CRC16 in the Kconfig.

The crc16() function is used to check the firmware validity, but
the library was not explicitly selected.

Fixes: 3c3673bd

 ("ptp: ocp: Add firmware header checks")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Vadim Fedorenko <vadfed@fb.com>
Link: https://lore.kernel.org/r/20220726220604.1339972-1-jonathan.lemon@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>