Set the memory ID for DRAMPower.

It seems that this field is not used by DRAMPower currently, but I could not
find a good reason to keep it uninitialized.

DRAMSys/simulator/src/simulation/Dram.h

@@ -175,6 +175,7 @@ struct Dram : sc_module
             memPowerSpec.vdd2    = Configuration::getInstance().memSpec.vDD2;
 
             MemorySpecification memSpec;
+            memSpec.id = Configuration::getInstance().memSpec.MemoryId;
             memSpec.memoryType = Configuration::getInstance().memSpec.MemoryType;
             memSpec.memTimingSpec = memTimingSpec;
             memSpec.memPowerSpec  = memPowerSpec;