flash_fp_mcu: Fix nocturne/nami kernelnext
flash_fp_mcu: Fix nocturne/nami kernelnext

Nocturne and Nami are legacy kernel v4.4 devices.
The spidev char device naming changed between their v4.4 and newer v5.4.
Since these devices have a kernelnext build+tests, we need an alternative
configuration that uses the new spidev name.

This is achieved by allowing for specific alt configs that match
the full platform name, like "nami-kernelnext". If a config is not
provided for the full platform name, it will fallback to using the
normal base config name, like "nami".

BRANCH=none
BUG=b:194004525
TEST=# Run the following commands on a nocturne, nocturne-kernelnext,
     # nami, nami-kernelnext, and hatch setups.
     #
     # Note, you get a kernelnext setup by flashing the base platform
     # device with an xbuddy line similar to
     # xbuddy://remote/nami-kernelnext/latest-dev/test
     scp util/flash_fp_mcu ${DUT_HOSTNAME}:/usr/local/bin/flash_fp_mcu
     ssh ${DUT_HOSTNAME} flash_fp_mcu --hello
     # Check that full platform name and base name was identified
     # correctly.
     # Check that it succeeded.

Signed-off-by: Craig Hesling <383db090fd8ef907a606ac8a9eccd2962bc489cf@chromium.org>
Change-Id: Ib2ad991291639ef33799abb4bc3379c1659f754d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3035686
Reviewed-by: Jora Jacobi <a455eebda9438f5c0fd456183401d9dc71c2c28e@google.com>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec