EMC voltage for Mariko; Fix #60; Show battery & voltage info in overlay on Erista

- From previous analysis, EMC voltage is set before AMS loads on Mariko, and will not be set again or changed afterwards.

- sys-clk-OC will take care of setting emc voltage on Mariko once it loads.

- OS will not hang at boot as it always boots with EMC @ 1600 MHz.

Source/Atmosphere/stratosphere/loader/source/oc/oc_test.hpp

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) Switch-OC-Suite
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#ifndef ATMOSPHERE_IS_STRATOSPHERE
+#include <algorithm>
+#include <cmath>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+
+typedef uint8_t  u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef int32_t  s32;
+typedef uint64_t u64;
+typedef int      Result;
+
+#define R_SUCCEEDED(arg)   (arg == 0)
+#define R_FAILED(arg)      (arg != 0)
+#define LOGGING(fmt, ...)  { printf(fmt "\n", ##__VA_ARGS__); }
+#define CRASH(msg, ...)    { fprintf(stderr, "%s\nFailed in %s!\n", msg, __PRETTY_FUNCTION__); exit(-1); }
+#define R_SUCCEED()        { return 0; }
+#define R_THROW(err)       { return err; }
+#define R_TRY(expr)        { Result _rc = (expr); if (R_FAILED(_rc)) { return _rc; } }
+#define R_UNLESS(expr, rc) { if (!(expr)) { return rc; } }
+
+#define R_DEFINE_ERROR_RESULT(name, rc)        \
+    inline Result Result##name() { return rc; }
+
+#endif