gpio: max730x: Remove kfree(ts) in __max730x_remove()

The memory for ts is allocated by devm_kzalloc now, so the kfree is not
required.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Juergen Beisert <jbe@pengutronix.de>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>