i2c: i801: Move i801_wait_intr and i801_wait_byte_done in the code

Move both functions to avoid forward declarations in a subsequent patch.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/a60ee54b-c5e8-4bdb-9f1f-8889f4dcd114@gmail.com