base,mem: Use the standard [[deprecated]] attribute.

The [[deprecated]] attribute is now standard, and so we don't need to
wrap it in our own macro any more.

Change-Id: I363df9a9c6b820dee8c21b1716335c0d15fbc62d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35216
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Tested-by: kokoro <noreply+kokoro@google.com>
3 files changed