Fix register names in maps

The map keys are going to be used as register names
in the setRegister function, so they should be lowercase.

vmmTblApp/src/vmm_tbl.h

@@ -38,7 +38,7 @@ protected:
   //Registers channels per hybrid, per VMM
   int vmmST_[HYBRIDS_PER_FEN][VMMS_PER_HYBRID];
   int vmmSC_[HYBRIDS_PER_FEN][VMMS_PER_HYBRID];
-  std::map<std::string, int(*)[VMMS_PER_HYBRID]> registers{{"ST", vmmST_}, {"SC", vmmSC_}};
+  std::map<std::string, int(*)[VMMS_PER_HYBRID]> registers{{"st", vmmST_}, {"sc", vmmSC_}};
 
 private:
   static constexpr const char *driverName = "VMMTbl";