configs: Use integer division in MESI_Three_Level.py

Same as:

https://gem5-review.googlesource.com/c/public/gem5/+/42883

Change-Id: I99ea04b3c6e1d2ce3ac8419440e0e949711d3b07
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/43485
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
1 file changed