Input: ct82c710 - remove a redundant serio_register_port()

We already call serio_register_port() in ct82c710_probe(),
thus remove a redundant serio_register_port() in ct82c710_init().

Looks like this bug is introduced by
916d83cf
"Input: ct82c710 - convert to the new platform device interface"

[dtor@mail.ru: also move printk to where we register port]
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>