Input: add device and factory template

src/common/logging/backend.cpp

@@ -71,6 +71,7 @@ namespace Log {
     CLS(Audio)                                                                                     \
     SUB(Audio, DSP)                                                                                \
     SUB(Audio, Sink)                                                                               \
+    CLS(Input)                                                                                     \
     CLS(Loader)
 
 // GetClassName is a macro defined by Windows.h, grrr...

src/common/logging/log.h

@@ -89,6 +89,7 @@ enum class Class : ClassType {
     Audio_DSP,         ///< The HLE implementation of the DSP
     Audio_Sink,        ///< Emulator audio output backend
     Loader,            ///< ROM loader
+    Input,             ///< Input emulation
     Count              ///< Total number of logging classes
 };