include: dt-bindings: pinctrl: stm32f1-afio: fix can & eth pinmap

The bindings for the stm32f105 afio pin remap had defined the wrong
offset for CAN and ETH.
This commit corrects those to the bits specified in RM0008 Rev.21,
but the changes could not be verfied on hw.

Signed-off-by: Thomas Stranger <thomas.stranger@outlook.com>