sim: added missed macro definition on MacOS

A recent patch add the use of the macro:
This macro is not very cross-platform, and needs to be
defined according to the platform.

This patch defines the missing macro on MacOS.

Change-Id: I582f69e652dc060b4532358141179ad6d37eafc7
Reviewed-by: Jason Lowe-Power <>
Maintainer: Brandon Potter <>
1 file changed