Since commit 607ca46e ('UAPI: (Scripted) Disintegrate include/linux') the
list of functionality constants moved to include/uapi/linux/i2c.h. Update the
reference accordingly.

Fixes: 607ca46e ('UAPI: (Scripted) Disintegrate include/linux')
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>