CMSIS_DAP: Change string encoding in DAP_Info from ASCII to UTF-8 (#973)

CMSIS/DoxyGen/DAP/src/dap_USB_cmds.txt

@@ -253,7 +253,7 @@ The <b>DAP_Info Command</b> provides configuration information about the Debug U
 
 - \b Len:  Info length in bytes.
 - \b Info:
-  - a \b string encoded in US ASCII. Len is the string length including the \\x00 terminator. Len = 0 indicates no information, and is distinct from an empty string indicated by Len = 1.
+  - a \b string encoded as UTF-8. Len is the string length including the \\x00 terminator. Len = 0 indicates no information, and is distinct from an empty string indicated by Len = 1.
   - a \b BYTE value (indicated with Len = 1).
   - a \b SHORT value (indicated with Len = 2).
   - a \b WORD value (indicated with Len = 4).