Perf: Bump T-Rex to 2.88

+ Mellanox 4.6 is not for Ubuntu 20.04
+ Mellanox for ubuntu 20.04 is 4.9+
+ T-Rex 2.86 is not for Mellanox 4.6+
+ T-Rex for Mellanox 5.2 is 2.88+
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= Bump

Signed-off-by: pmikus <pmikus@cisco.com>
Change-Id: I902dfc2a43e6718b385e89f31a34260e09d61bd3
(cherry picked from commit 6ec31b8aa67f4af2b963b3984f047e94ba790b3d)