build: Don't hardcode clutter-x11-1.0 in the .pc file
build: Don't hardcode clutter-x11-1.0 in the .pc file

Mx can be built with a "none" winsys for EGL flavours of clutter. Let's
not hardcode a clutter-x11-1.0 pkg-config dependency in the .pc file but
just require clutter-1.0 instead.

clutter-project/mx,clutter-project/mx,jonnylamb/mx,jonnylamb/mx,pwithnall/mx,pwithnall/mx,jonnylamb/mx,clutter-project/mx,pwithnall/mx,clutter-project/mx,pwithnall/mx,jonnylamb/mx