SIDK_S1SBP6A: fix to support rtc range from 0 to 0xEFFFFFFF

BP6A do not support from 0 to 0xEFFFFFFF in SOC.
This patch fixes it in s/w manner.

Signed-off-by: Heuisam Kwag <[email protected]>

Author: heuisam

targets/TARGET_Samsung/TARGET_SIDK_S1SBP6A/rtc_api.c

@@ -30,9 +30,10 @@
 #include "mbed_debug.h"
 
 #define BP6A_RTC_START_TIME     946684800
+#define BP6A_MAX_REG            0x0FFFFFFF
 static bool rtc_initialized = false;
 static bool g_before2000 = false;
-
+static time_t g_rtc_offset = 0;
 void rtc_init(void)
 {
     if (!rtc_initialized) {
@@ -73,6 +74,8 @@ time_t rtc_read(void)
         return 0;
     }
 
+    t += g_rtc_offset;
+
     if (g_before2000) {
         t -= BP6A_RTC_START_TIME;
     }
@@ -84,6 +87,12 @@ void rtc_write(time_t t)
     struct rtc_bcd_s rtc_val;
     struct tm timeinfo;
 
+    if (t > BP6A_MAX_REG) {
+        g_rtc_offset = t;
+        t = 0;
+    } else
+        g_rtc_offset = 0;
+
     /*BP6A : The implicit number of thousands place is 20.*/
     if (t < BP6A_RTC_START_TIME) {
         g_before2000 = true;