Those functions are defined in datapage.c, usually this file is added by the wizard as well. So you just need to add this file to your project, it is located in lib\hc12c\src.
Also note that HC12 V4.5's sprintf does not use _STORE_FAR_16 in its default configuration (I think there is a libdefs.h option). Not sure, but can be that previous versions of sprintf did reference it.
Daniel