Add BCD util tools

Author: cla7aye15I4nd

qiling/hw/utils/bcd.py

@@ -10,4 +10,7 @@ def byte2bcd(value):
         bcdhigh += 1
         value -= 10
 
-    return (bcdhigh << 4) | value
+    return (bcdhigh << 4) | value
+
+def bcd2byte(value):
+    return ((value & 0xF0) >> 0x4) * 10 + (value & 0xf)