gpio: pca953x: Use correct u16 value for register word write

commit 9b8e3ec3 upstream.

The current implementation only uses the first byte in val,
the second byte is always 0. Change it to use cpu_to_le16
to write the two bytes into the register
Signed-off-by: Yong Li <sdliyong@gmail.com>
Reviewed-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/gpio/gpio-pca953x.c

@@ -18,6 +18,7 @@
 #include <linux/i2c.h>
 #include <linux/platform_data/pca953x.h>
 #include <linux/slab.h>
+#include <asm/unaligned.h>
 #ifdef CONFIG_OF_GPIO
 #include <linux/of_platform.h>
 #endif
@@ -154,7 +155,7 @@ static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
 		switch (chip->chip_type) {
 		case PCA953X_TYPE:
 			ret = i2c_smbus_write_word_data(chip->client,
-							reg << 1, (u16) *val);
+			    reg << 1, cpu_to_le16(get_unaligned((u16 *)val)));
 			break;
 		case PCA957X_TYPE:
 			ret = i2c_smbus_write_byte_data(chip->client, reg << 1,