gpio: pca953x: define masks for addressing common and extended registers

These mask bits are to be used to map the extended register
addresses (which are defined for an unsupported 8-bit pcal chip)
to 16 and 24 bit chips (pcal6524).

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-pca953x.c

@@ -56,6 +56,10 @@
 #define PCAL6524_DEBOUNCE	0x2d
 
 #define PCA_GPIO_MASK		0x00FF
+
+#define PCAL_GPIO_MASK		0x1f
+#define PCAL_PINCTRL_MASK	0xe0
+
 #define PCA_INT			0x0100
 #define PCA_PCAL		0x0200
 #define PCA_LATCH_INT (PCA_PCAL | PCA_INT)