HID: core: allow concurrent registration of drivers

Detected on the Dell XPS 9365.

The laptop has 2 devices that benefit from the hid-generic auto-unbinding.
When those 2 devices are presented to the userspace, udev loads both wacom and
hid-multitouch. When this happens, the code in __hid_bus_reprobe_drivers() is
called concurrently and the second device gets reprobed twice.

An other bug in the power_supply subsystem prevent to remove the wacom driver
if it just finished its initialization, which basically kills the wacom node.

[jkosina@suse.cz: reformat changelog a bit]
Fixes c17a7476

 ("HID: core: rewrite the hid-generic automatic unbind")
Cc: stable@vger.kernel.org # v4.17
Tested-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>