Ensure all files are properly terminated

Since we use Unix text format, all lines, including the last one, should
be terminated by ASCII LF.

src/RTC_DS1307.cpp

@@ -131,4 +131,4 @@ uint8_t RTC_DS1307::readnvram(uint8_t address) {
 /**************************************************************************/
 void RTC_DS1307::writenvram(uint8_t address, uint8_t data) {
   writenvram(address, &data, 1);
-}
+}

src/RTC_Micros.cpp

@@ -30,4 +30,4 @@ DateTime RTC_Micros::now() {
   lastMicros += elapsedSeconds * microsPerSecond;
   lastUnix += elapsedSeconds;
   return lastUnix;
-}
+}

src/RTC_Millis.cpp

@@ -24,4 +24,4 @@ DateTime RTC_Millis::now() {
   lastMillis += elapsedSeconds * 1000;
   lastUnix += elapsedSeconds;
   return lastUnix;
-}
+}

src/RTC_PCF8523.cpp

@@ -289,4 +289,4 @@ void RTC_PCF8523::deconfigureAllTimers() {
 /**************************************************************************/
 void RTC_PCF8523::calibrate(Pcf8523OffsetMode mode, int8_t offset) {
   write_register(PCF8523_OFFSET, ((uint8_t)offset & 0x7F) | mode);
-}
+}