based on g_pcs_16bit

Provide the rate of the WR Reference Clock based on the information
about the width of the PCS word. It is assumed to be related:
* 16bit word with 62.5MHz clock
*  8bit word with  125MHz clock

WR Streamers need to be used with WR Reference clock of 62.5MHz,
adding generic to specify what ref_clk is used (125MHz by default,
or 62.5MHz)

The generic g_ref_clk_rate was dummy, i.e. never used. The module
pulse_stamper is used with input reference clock (and tm_cycles_i)
of 125MHz and 62.5MHz clock, in the wr_streamers. Added possibility
to define what clock is used (default 125MHz or 62.5MHz). In any
case, the output timestamp is of cycle period of 8ns.

no frames are transmitted/received, it only checked correctness of
transmission

added timeout to throw an error when no frames is received for an
unacceptable time

updates kintex7 phy name to reflect new peter_xilinx_phys convention
add clbv3 reference design files
last commit also needs artix7 support in xwrc_platform_xilinx.vhd
added BullsEye connections
CLBv3: moved dmtd div2 and buffer into xwrc_platform_xilinx.vhd
CLBv3: implementation files (including bmm)
CLBv3: Clean up

Conflicts:
	platform/xilinx/xwrc_platform_xilinx.vhd

added clbv2_ref_design files
added initial clbv2_ref_design ucf file
removed external wishbone busses (not used for clbv2_ref_design), free running clk_125m_pllref needed for reset synchronization
removed external wishbone busses (not used for clbv2_ref_design), free running clk_125m_pllref needed for reset synchronization, phy16
Merge branch 'peter_clbv2_ref_design' of ohwr.org:hdl-core-lib/wr-cores into peter_clbv2_ref_design
clk_20m_vcxo_i free running clock for reset gen. (thus no need for separate 125 MHz fpga input; remove clk_125m_pllref_p/n_i)
updates kintex7 phy name to reflect new peter_xilinx_phys convention
last commit also needs artix7 support in xwrc_platform_xilinx.vhd
CLBv2: reference clock is 62.5 MHz for 16 bit PHYs. Changed naming convention accordingly.
CLBv2: point proper bram file
CLBv2: implementation (including bmm)
CLBv2 reference design cleaned
CLBv2: updated (hdlmake made) Xilinx ISE project file

(cherry picked from commit 6d689ad2)

(cherry picked from commit 70bf1927)