Extract KeyMatrix_Init() and create related typedefs.

shared/key_matrix.h

@@ -0,0 +1,29 @@
+#ifndef __KEY_MATRIX_H__
+#define __KEY_MATRIX_H__
+
+// Includes:
+
+    #include "fsl_common.h"
+    #include "fsl_port.h"
+
+// Type definitions:
+
+    typedef struct {
+        PORT_Type *port;
+        GPIO_Type *gpio;
+        clock_ip_name_t clock;
+        uint32_t pin;
+    } key_matrix_pin_t;
+
+    typedef struct {
+        uint8_t colNum;
+        uint8_t rowNum;
+        key_matrix_pin_t *cols;
+        key_matrix_pin_t *rows;
+    } key_matrix_t;
+
+// Functions:
+
+    void KeyMatrix_Init(key_matrix_t keyMatrix);
+
+#endif