Renamed lvs guard to use_power_pins

- Also, added guard to the cells in the custom memory
- dropped DLVS from the dv Makefiles
diff --git a/verilog/rtl/caravel_clocking.v b/verilog/rtl/caravel_clocking.v
index ecf8215..1b1555f 100644
--- a/verilog/rtl/caravel_clocking.v
+++ b/verilog/rtl/caravel_clocking.v
@@ -1,7 +1,7 @@
 // This routine synchronizes the 
 
 module caravel_clocking(
-`ifdef LVS
+`ifdef USE_POWER_PINS
     input vdd1v8,
     input vss,
 `endif