net: wan: framer/pef2256: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Herve Codina <herve.codina@bootlin.com>
Link: https://lore.kernel.org/r/9684419fd714cc489a3ef36d838d3717bb6aec6d.1709886922.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: wan: framer: Add support for the Lantiq PEF2256 framer

The Lantiq PEF2256 is a framer and line interface component designed to
fulfill all required interfacing between an analog E1/T1/J1 line and the
digital PCM system highway/H.100 bus.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20231128132534.258459-4-herve.codina@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>