add: Sting 转 RegIndex 接口

src/main/java/com/iflytop/gd/hardware/type/RegIndex.java

@@ -177,5 +177,16 @@ public enum RegIndex {
         }
         return null;
     }
+
+    public static RegIndex fromString(String regStr)
+    {
+        RegIndex[] values = RegIndex.values();
+        for (RegIndex regindex : values) {
+            if (regindex.toString().equalsIgnoreCase(regStr)) {
+                return regindex;
+            }
+        }
+        return null;
+    }
 }