configure.ac: correct driglx-direct help text

The default was toggled a while back, but the text wasn't updated.

Fixes: bd526ec9e1 ("configure: Always default to
--enable-driglx-direct")
Cc: Jon TURNEY <jon.turney@dronecode.org.uk>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>

configure.ac

@@ -1598,7 +1598,7 @@ fi
 AC_ARG_ENABLE([driglx-direct],
     [AS_HELP_STRING([--disable-driglx-direct],
         [disable direct rendering in GLX and EGL for DRI \
-            @<:@default=auto@:>@])],
+            @<:@default=enabled@:>@])],
     [driglx_direct="$enableval"],
     [driglx_direct="yes"])