I used this procedure in Ubuntu:

sudo apt-get install -y bison build-essential curl flex git gnat libncurses5-dev m4 zlib1g-dev

git clone https://github.com/flashrom/flashrom.git
Cloning into 'flashrom'...
remote: Enumerating objects: 80, done.
remote: Counting objects: 100% (80/80), done.
remote: Compressing objects: 100% (58/58), done.
remote: Total 11610 (delta 39), reused 52 (delta 22), pack-reused 11530
Receiving objects: 100% (11610/11610), 4.07 MiB | 19.58 MiB/s, done.
Resolving deltas: 100% (8812/8812), done.
clay@clay-MS-7C37:~$ ls -al

cd flashrom

clay@clay-MS-7C37:~/flashrom$ sudo make install
...
cc -MMD -Os -Wall -Wextra -Wno-unused-parameter -Wshadow -Wmissing-prototypes -Wwrite-strings -Werror -I/usr/include/libusb-1.0  -D'CONFIG_DEFAULT_PROGRAMMER=PROGRAMMER_INVALID' -D'CONFIG_DEFAULT_PROGRAMMER_ARGS="''"' -D'CONFIG_INTERNAL=1' -D'CONFIG_INTERNAL_DMI=1' -D'CONFIG_ENE_LPC=1' -D'CONFIG_MEC1308=1' -D'CONFIG_SERPROG=1' -D'CONFIG_RAYER_SPI=1' -D'CONFIG_RAIDEN=1' -D'CONFIG_PONY_SPI=1' -D'CONFIG_BITBANG_SPI=1' -D'CONFIG_NIC3COM=1' -D'CONFIG_GFXNVIDIA=1' -D'CONFIG_SATASII=1' -D'CONFIG_ATAVIA=1' -D'CONFIG_IT8212=1'   -D'CONFIG_PICKIT2_SPI=1' -D'CONFIG_STLINKV3_SPI=1'   -D'CONFIG_DUMMY=1' -D'CONFIG_DRKAISER=1' -D'CONFIG_NICREALTEK=1' -D'CONFIG_NICINTEL=1' -D'CONFIG_NICINTEL_SPI=1' -D'CONFIG_NICINTEL_EEPROM=1' -D'CONFIG_OGP_SPI=1' -D'CONFIG_BUSPIRATE_SPI=1' -D'CONFIG_DEDIPROG=1' -D'CONFIG_DEVELOPERBOX_SPI=1' -D'CONFIG_SATAMV=1' -D'CONFIG_LINUX_MTD=1' -D'CONFIG_LINUX_SPI=1' -D'CONFIG_CH341A_SPI=1' -D'CONFIG_DIGILENT_SPI=1' -D'CONFIG_I2C_SUPPORT=1' -D'NEED_PCI=1'  -D'NEED_RAW_ACCESS=1' -D'NEED_LIBUSB1=1' -D'HAVE_UTSNAME=1' -D'HAVE_CLOCK_GETTIME=1' -D'FLASHROM_VERSION="v1.2-131-g74fd030"' -o chipset_enable.o -c chipset_enable.c
In file included from chipset_enable.c:36:
hwaccess.h:34:10: fatal error: pci/pci.h: No such file or directory
   34 | #include <pci/pci.h>
      |          ^~~~~~~~~~~
compilation terminated.
make: *** [Makefile:1271: chipset_enable.o] Error 1
clay@clay-MS-7C37:~/flashrom$

Looking at https://review.coreboot.org/cgit/flashrom.git/tree/

I don't find a pci.h file either. Any suggestions?

Clay