feat(mt8188): add pinctrl support

Add pinctrl support for MT8188.

TEST=build pass
BUG=b:236331724

Signed-off-by: Jianguo Zhang <jianguo.zhang@mediatek.corp-partner.google.com>
Change-Id: Id4ac8f67009621fff8f15f3ab2d8f200343c8356
diff --git a/plat/mediatek/include/mt8188/platform_def.h b/plat/mediatek/include/mt8188/platform_def.h
index 0b38c63..962d952 100644
--- a/plat/mediatek/include/mt8188/platform_def.h
+++ b/plat/mediatek/include/mt8188/platform_def.h
@@ -20,6 +20,15 @@
 #define MTK_DEV_RNG1_SIZE	(0x10000000)
 
 /*******************************************************************************
+ * GPIO related constants
+ ******************************************************************************/
+#define GPIO_BASE		(IO_PHYS + 0x00005000)
+#define IOCFG_RM_BASE		(IO_PHYS + 0x01C00000)
+#define IOCFG_LT_BASE		(IO_PHYS + 0x01E10000)
+#define IOCFG_LM_BASE		(IO_PHYS + 0x01E20000)
+#define IOCFG_RT_BASE		(IO_PHYS + 0x01EA0000)
+
+/*******************************************************************************
  * UART related constants
  ******************************************************************************/
 #define UART0_BASE	(IO_PHYS + 0x01002000)