iio: light: apds9960: fix wrong register for gesture gain

stable inclusion
from stable-v5.10.157
commit fa9efcbfbf77a9b727271935ba99385a4f2d36ee
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7MU59

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fa9efcbfbf77a9b727271935ba99385a4f2d36ee



--------------------------------

commit 0aa60ff5 upstream.

Gesture Gain Control is in REG_GCONF_2 (0xa3), not in REG_CONFIG_2 (0x90).

Fixes: aff268cd ("iio: light: add APDS9960 ALS + promixity driver")
Signed-off-by: Alejandro Concepcion-Rodriguez <asconcepcion@acoro.eu>
Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/EaT-NKC-H4DNX5z4Lg9B6IWPD5TrTrYBr5DYB784wfDKQkTmzPXkoYqyUOrOgJH-xvTsEkFLcVkeAPZRUODEFI5dGziaWXwjpfBNLeNGfNc=@acoro.eu


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>