Change in flashrom[master]: spi25_statusreg: make register read/write functions generic

[Nikolai Artemiev (Code Review)]

Attention is currently required from: Angel Pons, Nikolai Artemiev, Sergii Dmytruk.
Hello build bot (Jenkins), Nico Huber, Edward O'Callaghan, Angel Pons, Anastasia Klimchuk, Sergii Dmytruk,

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

https://review.coreboot.org/c/flashrom/+/58475

to look at the new patch set (#16).

Change subject: spi25_statusreg: make register read/write functions generic
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spi25_statusreg: make register read/write functions generic

This patch adds new spi_{read,write}_register() functions that take the
source/destination register as an argument. Currently they can only
access SR1, support for other registers will be added in another patch.

Since we're refactoring things, this commit also makes
spi_read_register() return an error code, making it possible to identify
error conditions that spi_read_status_register() concealed.

BUG=b:195381327,b:153800563
TEST=flashrom --wp-{enable,disable,range,list,status} at end of patch series
BRANCH=none

Change-Id: I0a3951bbf993f2d8d830143b29d3ce16cc6901d7
Signed-off-by: Nikolai Artemiev 
---
M chipdrivers.h
M flash.h
M spi25_statusreg.c
3 files changed, 76 insertions(+), 35 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/75/58475/16