include: dt-bindings: Add GPIO pin index definition for rockchip pinctrl

Add gpio pin index definition to make it easier to describe
GPIO in dts.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

include/dt-bindings/pinctrl/rockchip.h

@@ -25,6 +25,39 @@
 #define RK_GPIO4	4
 #define RK_GPIO6	6
 
+#define RK_PA0		0
+#define RK_PA1		1
+#define RK_PA2		2
+#define RK_PA3		3
+#define RK_PA4		4
+#define RK_PA5		5
+#define RK_PA6		6
+#define RK_PA7		7
+#define RK_PB0		8
+#define RK_PB1		9
+#define RK_PB2		10
+#define RK_PB3		11
+#define RK_PB4		12
+#define RK_PB5		13
+#define RK_PB6		14
+#define RK_PB7		15
+#define RK_PC0		16
+#define RK_PC1		17
+#define RK_PC2		18
+#define RK_PC3		19
+#define RK_PC4		20
+#define RK_PC5		21
+#define RK_PC6		22
+#define RK_PC7		23
+#define RK_PD0		24
+#define RK_PD1		25
+#define RK_PD2		26
+#define RK_PD3		27
+#define RK_PD4		28
+#define RK_PD5		29
+#define RK_PD6		30
+#define RK_PD7		31
+
 #define RK_FUNC_GPIO	0
 #define RK_FUNC_1	1
 #define RK_FUNC_2	2