power: supply: wm8350-power: Add missing free in free_charger_irq

In free_charger_irq(), there is no free for 'WM8350_IRQ_CHG_FAST_RDY'.
Therefore, it should be better to add it in order to avoid the memory leak.

Fixes: 14431aa0 ("power_supply: Add support for WM8350 PMU")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>