Use TLS v1.3 PSK callback in extension allow for one call in client

New compile time option WOLFSSL_PSK_ONE_ID. Indicates one identity
available. No need for client to call callback when generating binder -
already cached.

configure.ac

@@ -1662,6 +1662,20 @@ AC_ARG_ENABLE([psk],
     [ ENABLED_PSK=no ]
     )
 
+# Single PSK identity
+AC_ARG_ENABLE([psk-one-id],
+    [AS_HELP_STRING([--enable-psk-one-id],[Enable PSK (default: disabled)])],
+    [ ENABLED_PSK_ONE_ID=$enableval ],
+    [ ENABLED_PSK_ONE_ID=no ]
+    )
+if test "$ENABLED_PSK_ONE_ID" = "yes"
+then
+    if test "$ENABLED_PSK" = "no"
+    then
+        ENABLED_PSK="yes"
+    fi
+    AM_CFLAGS="$AM_CFLAGS -DWOLFSSL_PSK_ONE_ID"
+fi
 
 # ERROR STRINGS
 AC_ARG_ENABLE([errorstrings],