stac_store_hints() does utterly wrong for masking the values for
gpio_dir and gpio_data, likely due to copy&paste errors.  Fortunately,
this feature is used very rarely, so the impact must be really small.

Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>