libflashrom,writeprotect: add functions for reading/writing WP configs

New functions are exposed through the libflashrom API for
reading/writing chip's WP settins: `flashrom_wp_{read,write}_cfg()`.

They read/write an opaque `struct flashrom_wp_cfg` instance, which
includes the flash protection range and status register protection mode.

This commit also adds `{read,write}_wp_bits()` helper functions that
read/write chip-specific WP configuration bits.

Tested: flashrom --wp-{enable,disable,range,list,status} at end of patch series

Change-Id: I3ad25708c3321b8fb0216c3eaf6ffc07616537ad
Signed-off-by: Nikolai Artemiev <nartemiev@google.com>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/58479
Original-Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
Original-Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/70968
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
6 files changed