extcon: Set parent device of extcon device using prameter of devm_extcon_dev_allocate

This patch set the parent device of extcon device using first parameter of
devm_extco_dev_allocate() to remove duplicate code on all of extcon provider
drivers.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Reported-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Tested-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Cc: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Graeme Gregory <gg@slimlogic.co.uk>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>