soc/mediatek: mtk-devapc: Convert to platform remove callback returning void

soc/mediatek: mtk-devapc: Convert to platform remove callback returning void

[ Upstream commit a129ac3555c0dca6f04ae404dc0f0790656587fb ]

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.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230925095532.1984344-15-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Stable-dep-of: c9c0036c1990 ("soc: mediatek: mtk-devapc: Fix leaking IO map on driver remove")
Signed-off-by: Sasha Levin <sashal@kernel.org>