util,systemc: Update the stats API used in one of the examples.

util,systemc: Update the stats API used in one of the examples.

A new parameter as added to the initText method in March of this year,
but this example code was not updated which prevents it from compiling.

This change adds the parameter to the call and sets it to what the
documenting comments say is the default, true.

Change-Id: Ic8da46dba03f01f338c38a7bc02ba232a90ae349
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/32641
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>