configs: Add --machine-type option to baremetal.py
configs: Add --machine-type option to baremetal.py

Change-Id: Ie5d81b455b86f456a49ba91aa231169be319fa73
Signed-off-by: Giacomo Travaglini <8eef13a4f970e2e9372c8d26ad0737b760f99c02@arm.com>
Reviewed-by: Adrian Herrera <0f7a8031d49cb35713856aa725eb9889c7627fd9@arm.com>
Reviewed-by: Ciro Santilli <f9f94c17362144ef13d3dda5cd3efb8325112763@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27952
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5