iio: proximity: irsd200: Drop unused include

The driver includes the legacy GPIO header <linux/gpio.h> but doesn't
use any symbols from it. Drop it.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Waqar Hameed <waqar.hameed@axis.com>
Link: https://lore.kernel.org/r/20231128-descriptors-iio-v1-1-da1e94755db6@linaro.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/proximity/irsd200.c

@@ -7,7 +7,6 @@
 
 #include <asm/unaligned.h>
 #include <linux/bitfield.h>
-#include <linux/gpio.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/regmap.h>