Adding McHCK flash reload function and some cleanup.

- Requires special string to be compared with the bootloader and VBAT register file

Lib/mk20dx.c

@@ -49,7 +49,7 @@ extern unsigned long _estack;
 
 // ----- Function Declarations -----
 
-extern int main ();
+extern int main();
 void ResetHandler();
 
 

Lib/mk20dx.h

@@ -1957,6 +1957,9 @@ typedef struct {
 #define ARM_DWT_CTRL_CYCCNTENA          (1 << 0)                // Enable cycle count
 #define ARM_DWT_CYCCNT          *(volatile uint32_t *)0xE0001004 // Cycle count register
 
+// Other
+#define VBAT                    *(volatile uint8_t *)0x4003E000 // Register available in all power states
+
 extern int nvic_execution_priority(void);
 
 extern void nmi_isr(void);