timing constraints to just SATA controller w/o the common ones

x393_sata/ahci_timing_frag.xdc

+# external clock 150Mhz
+create_clock -name gtrefclk -period 6.666 -waveform {0.000 3.333} [get_nets sata_top/ahci_sata_layers_i/phy/gtrefclk]
+
+# recovered sata parallel clock
+create_clock -name rx_clk -period 6.666 -waveform {0.000 3.333} [get_nets sata_top/ahci_sata_layers_i/phy/gtx_wrap/xclk_gtx]
+create_clock -name txoutclk -period 6.666 -waveform {0.000 3.333} [get_nets sata_top/ahci_sata_layers_i/phy/gtx_wrap/txoutclk_gtx]
+
+create_clock -name usrclk2 -period 13.333 -waveform {0.000 6.666} [get_nets sata_top/ahci_sata_layers_i/phy/usrclk2_r]
+
+
+set_clock_groups -name async_clocks -asynchronous \
+-group {gtrefclk} \
+-group {rx_clk} \
+-group {usrclk2} \
+-group {txoutclk}