platform/x86: wmi: Make remove callback return void

The driver core ignores the return value of struct bus_type::remove()
(and so wmi_dev_remove()) because there is only little that can be done.

To simplify the quest to make this function return void, let struct
wmi_driver::remove() return void, too. All implementers of this callback
return 0 already and this way it should be obvious to driver authors
that returning an error code is a bad idea.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20210301160404.1677064-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: Move all dell drivers to their own subdirectory

A user without a Dell system doesn't need to pick any of these
drivers.

Users with a Dell system can enable this submenu and all drivers
behind it will be enabled.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Link: https://lore.kernel.org/r/20210203195832.2950605-1-mario.limonciello@dell.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>