RTC: Write 0 tot he counter bias if we are on custom RTC

This can be considered a hack, but it essentially neuter the bias applied on boot for both console on the RTC.  This avoids having the time on boot be changes significantly while the user would want a specific RTC and it also avoids possible underflow of the RTC if it is near the epoch.

Source/Core/Core/ConfigLoaders/BaseConfigLoader.cpp

@@ -20,6 +20,7 @@
 
 #include "Core/Config/SYSCONFSettings.h"
 #include "Core/ConfigLoaders/IsSettingSaveable.h"
+#include "Core/ConfigManager.h"
 #include "Core/Core.h"
 #include "Core/IOS/IOS.h"
 #include "Core/IOS/USB/Bluetooth/BTBase.h"
@@ -49,6 +50,9 @@ void SaveToSYSCONF(Config::LayerType layer)
         setting.config_info);
   }
 
+  if (SConfig::GetInstance().bEnableCustomRTC)
+    sysconf.SetData<u32>("IPL.CB", SysConf::Entry::Type::Long, 0);
+
   // Disable WiiConnect24's standby mode. If it is enabled, it prevents us from receiving
   // shutdown commands in the State Transition Manager (STM).
   // TODO: remove this if and once Dolphin supports WC24 standby mode.
@@ -177,4 +181,4 @@ std::unique_ptr<Config::ConfigLayerLoader> GenerateBaseConfigLoader()
 {
   return std::make_unique<BaseConfigLayerLoader>();
 }
-}
+}  // namespace ConfigLoaders

Source/Core/Core/HW/EXI/EXI_DeviceIPL.cpp

@@ -129,6 +129,8 @@ CEXIIPL::CEXIIPL() : m_uPosition(0), m_uAddress(0), m_uRWOffset(0), m_FontsLoade
   // We Overwrite language selection here since it's possible on the GC to change the language as
   // you please
   g_SRAM.lang = SConfig::GetInstance().SelectedLanguage;
+  if (SConfig::GetInstance().bEnableCustomRTC)
+    g_SRAM.counter_bias = 0;
   FixSRAMChecksums();
 
   Common::WriteProtectMemory(m_pIPL, ROM_SIZE);