kernel|lib: change driver name and device name

The name 'ft' is not meaningful for everyone

Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
kernel: coalescing 40 tstamp/40ms

Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
kernel: clear IRQ

Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
kernel: use IRQ_NONE instead of '0'

Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
kernel: add WR calibration offset
kernel: apply WR timebase offset on readout
style: checkpatch fixes

Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
kernel: ugly hacks to get the driver to work with a Fine Delay in one slot and FMC-TDC in the other
kernel: hacks to make reset work (still not portable to bitstreams containing anything else than 2 TDC cores)
kernel: use 'enumerate n-th' mezzanine up to current slot scheme to allow bitstreams with different FMCs