bus: sun50i-de2: 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.

Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20231109202830.4124591-7-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

bus: sun50i-de2: Adjust printing error message

SRAM driver often returns -EPROBE_DEFER and thus this bus driver often
prints error message, even if it probes successfully later. This is
confusing for users and they often think that something is wrong.

Use dev_err_probe() helper for printing error message. It handles
-EPROBE_DEFER automatically.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20211010071812.145178-1-jernej.skrabec@gmail.com

bus: add bus driver for accessing Allwinner A64 DE2

The "Display Engine 2.0" (usually called DE2) on the Allwinner A64 SoC
is different from the ones on other Allwinner SoCs. It requires a SRAM
region to be claimed, otherwise all DE2 subblocks won't be accessible.

Add a bus driver for the Allwinner A64 DE2 part which claims the SRAM
region when probing.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>