platform/x86/intel: bytcrc_pwrsrc: 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>
Link: https://lore.kernel.org/r/20230927081040.2198742-21-u.kleine-koenig@pengutronix.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: Add intel_bytcrc_pwrsrc driver

Add a new driver for the power-, wake- and reset-source functionality
of the Bay Trail (BYT) version of the Crystal Cove PMIC.

The main functionality here is detecting which power-sources (USB /
DC in / battery) are active. This is normally exposed to userspace as
a power_supply class charger device with an online sysfs attribute.

But if a charger is online or not is already exposed on BYT-CRC devices
through either an ACPI AC power_supply device, or through a native driver
for the battery charger chip (e.g. a BQ24292i).

So instead of adding duplicate info under the power_supply class this
driver exports the info through debugfs and likewise adds debugfs files
for the reset- and wake-source info / registers.

Despite this driver only exporting debugfs bits it is still useful to
have this driver because it clears the wake- and reset-source registers
after reading them. Not clearing these can have undesirable side-effects.

Specifically if the WAKESRC register contains 0x01 (wake by powerbutton)
on reboot then the firmware on some tablets turns the reboot into
a poweroff. I guess this may be necessary to make long power-presses turn
into a poweroff somehow?

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230303221928.285477-1-hdegoede@redhat.com