gpio: pca953x: add more register definitions for pcal6524

The pcal6524 has another set of registers to fine control
the interrupt handling.

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

@@ -49,6 +49,12 @@
 #define PCAL953X_INT_STAT	0x26
 #define PCAL953X_OUT_CONF	0x27
 
+#define PCAL6524_INT_EDGE	0x28
+#define PCAL6524_INT_CLR	0x2a
+#define PCAL6524_IN_STATUS	0x2b
+#define PCAL6524_OUT_INDCONF	0x2c
+#define PCAL6524_DEBOUNCE	0x2d
+
 #define PCA_GPIO_MASK		0x00FF
 #define PCA_INT			0x0100
 #define PCA_PCAL		0x0200