sysclk: code cleanup and fan speed

also fix incompatibility with nx fancontrol

Source/sys-clk/common/include/rgltr.h

@@ -0,0 +1,19 @@
+#pragma once
+#include <switch.h>
+#include "pcv_types.h"
+
+typedef struct {
+    Service s;
+} RgltrSession;
+
+Result rgltrInitialize(void);
+
+void rgltrExit(void);
+
+Service* rgltrGetServiceSession(void);
+
+Result rgltrOpenSession(RgltrSession* session_out, PowerDomainId module_id);
+void rgltrCloseSession(RgltrSession* session);
+Result rgltrGetVoltage(RgltrSession* session, u32 *out_volt);
+Result rgltrGetPowerModuleNumLimit(u32 *out);
+Result rgltrGetVoltageEnabled(RgltrSession* session, u32 *out);