timing/pulse_stamper: replace hand-written CDC chains with gc_[sync|pulse_synchronizer] for the ease of constraint definition

wr_softpll_ng: remove builtin frequency monitor, as the WRPCv5 will have a full blown FreqMon core integrated

Forgot to do that when porting the MDIO stuff to Cheby. Sorry Tristan :/

- we now use Cheby for the MDIO register layout (small changes in the naming)
- dropped LPC_CTRL/LPC_STAT registers in favour of a full WB master interface to the PHY.

wr_endpoint: assume Endpoint's private sub-cores are always present. No need to declare them as components.

Kintex7 LPDC now has a proper WB interface for the LPDC/Xilinx DRP registers.

Follow up in the Endpoint/PCS HDL in the subsequent commits

(use with wrpc-sw freqmon command)

through the numerous layers of wrappers... :/

add files for gthe4-lp implementation

See merge request !4

no upper bound for etherbone