RTC revamp (#1867)

* get this started

* implement DSi RTC commands

* set up RTC clock timer. lay down basic idea of a clock.

* make the date/time registers writable

* move RTC state to its own structure, to make it easier to deal with

* more RTC work
lay base for date/time dialog

* get the bulk of the RTC functionality going

* much simpler design for RTC stuff

* aha, that is what it is

* start working on the RTC IRQ

* implement all types of RTC IRQ

* start refining sleep mode. code still kinda sucks.

* implement keypad IRQ

* refine it some more

* shut the fuck uuuuuupppppppppppppp

src/frontend/qt_sdl/Platform.cpp

@@ -23,6 +23,7 @@
 #include <string>
 #include <QStandardPaths>
 #include <QString>
+#include <QDateTime>
 #include <QDir>
 #include <QThread>
 #include <QSemaphore>
@@ -610,6 +611,15 @@ void WriteFirmware(const SPI_Firmware::Firmware& firmware, u32 writeoffset, u32
 
 }
 
+void WriteDateTime(int year, int month, int day, int hour, int minute, int second)
+{
+    QDateTime hosttime = QDateTime::currentDateTime();
+    QDateTime time = QDateTime(QDate(year, month, day), QTime(hour, minute, second));
+
+    Config::RTCOffset = hosttime.secsTo(time);
+    Config::Save();
+}
+
 bool MP_Init()
 {
     return LocalMP::Init();