The bq24022 driver is just a specialised form of a gpio-regulator.

As all former users of it now use the gpio-regulator directly, there
is no need to keep it around.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NHaojian Zhuang <haojian.zhuang@gmail.com>