misc: Remove the "fault" parameter from syscall functions.

misc: Remove the "fault" parameter from syscall functions.

This parameter was never set or used, just plumbed everywhere,
occasionally with a dummy value. This change removes all of that
plumbing.

Change-Id: I9bc31ffd1fbc4952c5d3096f7f21eab30102300b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33277
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>