Improve sceIoGetDevType() return values.

At least for block/file devices.  Can't find a way to get an alias.

Core/FileSystems/ISOFileSystem.h

@@ -40,6 +40,7 @@ public:
 	PSPFileInfo GetFileInfo(std::string filename);
 	bool     OwnsHandle(u32 handle);
 	int      Ioctl(u32 handle, u32 cmd, u32 indataPtr, u32 inlen, u32 outdataPtr, u32 outlen, int &usec);
+	int      DevType(u32 handle);
 
 	size_t WriteFile(u32 handle, const u8 *pointer, s64 size);
 	bool GetHostPath(const std::string &inpath, std::string &outpath) {return false;}