[L] Change in flashrom[main]: cli_client: Add rpmc command support

[Matti Finder (Code Review)]

Attention is currently required from: Matti Finder, Peter Marheine.

Hello Anastasia Klimchuk, Peter Marheine, build bot (Jenkins),

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

https://review.coreboot.org/c/flashrom/+/84840?usp=email

to look at the new patch set (#14).

The following approvals got outdated and were removed:
Code-Review+2 by Peter Marheine, Verified+1 by build bot (Jenkins)

Change subject: cli_client: Add rpmc command support
......................................................................

cli_client: Add rpmc command support

This commit adds uses the new rpmc command implementation to
add them as a new feature to the cli_client.
Also adds the necessary documentation for this new feature.

Tested on the Winbond W25R128JV as a 'SFDP-capable chip'.

This patch was done to add rpmc command support to flashrom.
This enables users to write root keys to their flash chips while they
flash data on the chip. This might become useful in the future as rpmc
support is extended in coreboot.
Also adds debug tools to flashrom, which might be useful in
implementing coreboots rpmc support.

Change-Id: I36c823bbee65f256eb6edabe6f058321c9a0cfa1
Signed-off-by: Matti Finder 
---
M cli_classic.c
M doc/classic_cli_manpage.rst
M doc/dev_guide/building_from_source.rst
M doc/release_notes/devel.rst
4 files changed, 307 insertions(+), 7 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/40/84840/14