tdcdtc: TDC+DTC wishbone peripheral

either generic or spartan6 ioserdes2 based
software/tdcdtc: add example/test app
memtest: shrink memtest space from 64M to 32M

for smaller platforms like the lx9 microboard
remaining changes for lx9 microboard
lx9 impact script for its embedded closed source jtag
add tdcdtc to lx9