can: tcan4x5x: Remove checking the wake pin

Remove checking the wake pin for every read/write call.
The device is not explicitly put to sleep in the code
and the POR interrupt is cleared during the init of
the device.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>