base: Add function to saturate SatCounter

Create a saturation function for the SatCounter that makes its
internal counter reach its maximum value.

Change-Id: Ibd30fa27c4ae2714dd48e3eba85addd035fb737c
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20451
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed