bring in fwup/mtd-util/flashrom support for flashing internal spi

[SolidHal]

https://notabug.org/libreboot/libreboot/issues/714 has some relevant info

[SolidHal]

prawn@PrawnOS:~$ sudo flashrom -p internal -V
flashrom  on Linux 5.4.29-gnu (armv7l)
flashrom is free software, get the source code at https://flashrom.org

flashrom was built with libpci 3.5.2, GCC 8.2.0, little endian
Command line (3 args): flashrom -p internal -V
Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns).
Initializing internal programmer
pcilib: Cannot open /proc/bus/pci
pcilib: Cannot find any working access method.

[SolidHal]

prawn@PrawnOS:~$ sudo flashrom -p linux_mtd -V
flashrom  on Linux 5.4.29-gnu (armv7l)
flashrom is free software, get the source code at https://flashrom.org

Error: Unknown programmer "linux_mtd". Valid choices are:
internal, dummy, gfxnvidia, drkaiser, satasii, atavia, it8212, ft2232_spi,
serprog, buspirate_spi, dediprog, pony_spi, nicintel, nicintel_spi,
nicintel_eeprom, ogp_spi, linux_spi, usbblaster_spi, pickit2_spi, ch341a_spi.
Please run "flashrom --help" for usage info.

[SolidHal]

updated flashrom from testing
sudo apt install -t testing flashrom and got better results with mtd:

prawn@PrawnOS:~$ sudo flashrom -p linux_mtd -V
flashrom v1.2 on Linux 5.4.29-gnu (armv7l)
flashrom is free software, get the source code at https://flashrom.org

flashrom was built with libpci 3.6.4, GCC 9.2.1 20200224, little endian
Command line (3 args): flashrom -p linux_mtd -V
Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns).
Initializing linux_mtd programmer
get_mtd_info: device_name: "spi2.0", is_writeable: 1, numeraseregions: 0, total_size: 4194304, erasesize: 4096
Opened /dev/mtd0 successfully
The following protocols are supported: Programmer-specific.
Probing for Programmer Opaque flash chip, 0 kB: Found Programmer flash chip "Opaque flash chip" (4096 kB, Programmer-specific) on linux_mtd.
Found Programmer flash chip "Opaque flash chip" (4096 kB, Programmer-specific).
No operations were specified.