base,tests: Convert cprintftime from a "UnitTest" to a normal bin.

base,tests: Convert cprintftime from a "UnitTest" to a normal bin.

This "UnitTest" was really not a unit test, it was a timing utility for
measuring the performance of gem5's cprintf implementation. The name was
misleading, but more than that, it was linked against all of gem5 which
created a approximately 1.5 gigabyte binary for what is a very small
program.

Instead, the new version of cprintftime, which has the same
functionality as the old version, weighs in at a svelte 500k with debug
information.

This also trims down the number of misleading "UnitTest" entries to 3,
getting us closer to the point where we can eliminate that type of
entity entirely.

Change-Id: Id30d094f2844e948fe67e820c89412f8667aaa52
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40617
Maintainer: Gabe Black <gabe.black@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>