Minor nit about okHostClk in UCF file

In the XEM6310 UCF file (maybe others, haven’t looked) the period constraint on okHostClk is 9.96 ns. It should be 9.92 ns, corresponding to 100.8 MHz. Shouldn’t really be a problem (are you really going to miss timing by 0.4 MHz?) but it did generate a warning in ISE about periods not matching when I put my own CLKIN1_PERIOD generic in a PLL.