sim-se: correct statfs inclusion on !linux host

- Added missing header
- Fixed typo on __linux__ macro conditional
- s/ifdef/if defined/g for consistency

Change-Id: I83b69856e5ec8b23b707642c0e14216cf62db31e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18668
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed