TCG ist used for all the supported QEMU targets right now. I successfully booted the Coldfire test kernel that is available from the download page.
EDIT:
There doesn't seem to be any MMU emulation yet, though:
Code:
# cat cpuinfo
CPU: COLDFIRE(m520x)
MMU: none
FPU: none
Clocking: 208.8MHz
BogoMips: 139.26
Calibration: 69632000 loops