Agptek Rocker: Implement RTC support

Add define in config file to enable RTC support in rockbox,
Fix time_menu.c to include radio.h only when tuner is present
Implement time setting function on linux (was empty stub)

Not tested.

Change-Id: I40e6c4a6c1b66ada9cf4e698e502e221d0fc44df

apps/menus/time_menu.c

@@ -37,7 +37,9 @@
 #include "list.h"
 #include "alarm_menu.h"
 #include "screens.h"
+#if CONFIG_TUNER
 #include "radio.h"
+#endif
 #include "font.h"
 #include "system.h"
 

firmware/export/config/agptekrocker.h

@@ -59,7 +59,7 @@
 #define CONFIG_BACKLIGHT_FADING BACKLIGHT_FADING_SW_SETTING
 
 /* define this if you have a real-time clock */
-#define CONFIG_RTC 0
+#define CONFIG_RTC APPLICATION
 
 /* The number of bytes reserved for loadable codecs */
 #define CODEC_SIZE 0x80000

firmware/target/hosted/rtc.c

@@ -9,6 +9,7 @@
  *
  * Based upon code (C) 2002 by Björn Stenberg
  * Copyright (C) 2011 by Thomas Jarosch
+ * Copyright (C) 2018 by Marcin Bukat
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -20,6 +21,7 @@
  *
  ****************************************************************************/
 #include <time.h>
+#include <sys/time.h>
 
 void rtc_init(void)
 {
@@ -35,6 +37,10 @@ int rtc_read_datetime(struct tm *tm)
 
 int rtc_write_datetime(const struct tm *tm)
 {
-    (void)tm;
-    return -1;
+    struct timeval tv;
+    
+    tv.tv_sec = mktime((struct tm *)tm);
+    tv.tv_usec = 0;
+
+    return settimeofday(&tv, NULL);
 }