sim-se: Ignore unimplemented system call

sim-se: Ignore unimplemented system call

System call sched_setaffinity causes crashes when running programs
that use ROCm. Ignoring the system call allows for the programs
to run to completion.

Change-Id: I27c767ef81091789e228d47f2bb5f6fa18f11539
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30154
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>