[M] Change in coreboot[master]: util/scripts: Add script to show platforms, CPU, type, and date added

[Martin L Roth (Code Review)]

Attention is currently required from: Felix Singer, Raul Rangel, Martin L Roth, Stefan Reinauer, Nicholas Chin.

Hello Felix Singer, build bot (Jenkins), Raul Rangel, Stefan Reinauer, Nicholas Chin,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/63799

to look at the new patch set (#4).

Change subject: util/scripts: Add script to show platforms, CPU, type, and date added
......................................................................

util/scripts: Add script to show platforms, CPU, type, and date added

This is the script used to generate the list of platforms that were
removed from the master branch at each release.  Generate a list for the
old branch, another for the new, and compare the two.

Representative output:
```eval_rst
+-------------------------+-------------------+------------+----------+
| Vendor/Board            | Processor         | Date added | Brd type |
+=========================+===================+============+==========+
| 51nb/x210               | INTEL_KABYLAKE    | 2020-03-16 | laptop   |
| acer/aspire_vn7_572g    | INTEL_SKYLAKE     | 2022-01-28 | laptop   |
| acer/g43t-am3           | INTEL_X4X         | 2020-09-28 | desktop  |
| amd/bilby               | AMD_PICASSO       | 2021-02-17 | eval     |
| amd/birman              | AMD_MORGANA       | 2022-10-10 | eval     |
| system76/whl-u          | INTEL_WHISKEYLAKE | 2021-04-14 | laptop   |
| ti/beaglebone           | TI_AM335X         | 2013-05-26 | sbc      |
| up/squared              | INTEL_APOLLOLAKE  | 2019-05-22 | mini     |
+-------------------------+-------------------+------------+----------+
```

Signed-off-by: Martin Roth 
Change-Id: I4f7265d95df31f3a74aa2aa164f6a094c1139750
---
M util/scripts/description.md
A util/scripts/show_platforms.sh
2 files changed, 80 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/99/63799/4