dev-arm: Don't use args and kwargs on attachIO

dev-arm: Don't use args and kwargs on attachIO

This is matching the attachOnChipIO style, and fixing the error of the
dma_ports kwarg being forwarded to the _attach_mem

Change-Id: Ib3ecf2fc18c488d938bbbf63eab3d7693cdb7d06
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27086
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>