The functions mappedGeometryRef and mappedGeometryUnref are API
functions ([1]) but were implemented in the geometry channel.
In case FreeRDP was built with BUILTIN_CHANNELS=OFF those functions
weren't available globally but used by the video channel.
Now the functions are fixed part of the freerdp-client library and
therefore available for all channels.
[1] exported in freerdp/client/geometry.h
Fixes#6236
