powerpc/platforms/83xx/suspend: Prevent unloading the driver

Returning an error in .remove() doesn't prevent a driver from being
unloaded. On unbind this only results in an error message, but the
device is remove anyhow.

I guess the author's idea of just returning -EPERM in .remove() was to
prevent unbinding a device. To achieve that set the suppress_bind_attrs
driver property and drop the useless .remove callback.

This is a preparation for making platform remove callbacks return void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220707061441.193869-2-u.kleine-koenig@pengutronix.de