stm32RTC can give the hour Format 24 or 12 hours

Adding a boolean (true) if the Hour format is 24 Hours.

Signed-off-by: Francois RAMU <frq09495@lmecxd0404.lme.st.com>

Author: Francois RAMU

README.md

@@ -190,6 +190,12 @@ underflow. Used by STM32LoRaWAN.
 Refer to the Arduino RTC documentation for the other functions
 http://arduino.cc/en/Reference/RTC
 
+### Since STM32RTC version higher than 1.4.0
+_IsFormat_24Hour_
+
+Returns True if the current Hour Format is HOUR_24 else false if Hour format is HOUR_12
+
+
 ## Source
 
 Source files available at:

src/STM32RTC.h

@@ -240,6 +240,10 @@ class STM32RTC {
     {
       return RTC_IsConfigured();
     }
+    bool isFormat_24hour(void)
+    {
+      return (_format == HOUR_24);
+    }
     bool isAlarmEnabled(Alarm name = ALARM_A);
     bool isTimeSet(void)
     {