mbed-client-cli: Remove support for ARM Compiler 5

ARM Compiler 5 is no longer actively supported and was superseded in
Mbed OS by ARM Compiler 6.

Author: hugueskamba

features/frameworks/mbed-client-cli/mbed-client-cli/ns_cmdline.h

@@ -128,7 +128,7 @@ uint8_t cmd_history_size(uint8_t max);
  *  This function should be used when user want to print something to the console
  *  \param fmt   console print function (like printf)
  */
-#if defined(__GNUC__) || defined(__CC_ARM)
+#if defined(__GNUC__)
 void cmd_printf(const char *fmt, ...)  __attribute__((__format__(__printf__, 1, 2)));
 #else
 void cmd_printf(const char *fmt, ...);
@@ -138,7 +138,7 @@ void cmd_printf(const char *fmt, ...);
  *  \param fmt  The format string is a character string, beginning and ending in its initial shift state, if any. The format string is composed of zero or more directives.
  *  \param ap   list of parameters needed by format string. This must correspond properly with the conversion specifier.
  */
-#if defined(__GNUC__) || defined(__CC_ARM)
+#if defined(__GNUC__)
 void cmd_vprintf(const char *fmt, va_list ap)  __attribute__((__format__(__printf__, 1, 0)));
 #else
 void cmd_vprintf(const char *fmt, va_list ap);