use 16bit uint for msp430fr overflow counter

include/arch/msp430fr5994lp/driver/counter.h

@@ -5,7 +5,7 @@
 #include <stdint.h>
 
 typedef uint16_t counter_value_t;
-typedef uint8_t counter_overflow_t;
+typedef uint16_t counter_overflow_t;
 
 class Counter {
 	private:
@@ -13,7 +13,7 @@ class Counter {
 
 	public:
 		uint16_t value;
-		volatile uint8_t overflow;
+		volatile uint16_t overflow;
 
 		Counter() : overflow(0) {}
 

src/arch/msp430fr5994lp/driver/counter.cc

@@ -6,7 +6,7 @@ Counter counter;
 __attribute__((interrupt(TIMER2_A1_VECTOR))) void handle_timer2_overflow()
 {
 	if (TA2IV == 0x0e) {
-		if (counter.overflow < 255) {
+		if (counter.overflow < 65535) {
 			counter.overflow++;
 		}
 	}