lock_chip: update documentation for skylake+

Signed-off-by: Thierry Laurion <[email protected]>

initrd/bin/lock_chip

@@ -1,9 +1,9 @@
 #!/bin/sh
 # For this to work:
-#  - io386 module needs to be enabled in board config (sandy/ivy/haswell know to work)
-#  - coreboot config need to enable CONFIG_BOOTMEDIA_LOCK_CONTROLLER=y without enabling CONFIG_INTEL_CHIPSET_LOCKDOWN
+#  - io386 module needs to be enabled in board config
+#  - <Skylake: coreboot config need to enable CONFIG_BOOTMEDIA_LOCK_CONTROLLER=y without enabling CONFIG_INTEL_CHIPSET_LOCKDOWN
+#  - >=Skylake: same as above and CONFIG_SOC_INTEL_COMMON_SPI_LOCKDOWN_SMM=y, CONFIG_SPI_FLASH_SMM=y and mode (eg: CONFIG_BOOTMEDIA_LOCK_WHOLE_RO=y)
 #  - Heads is actually doing the CONFIG_INTEL_CHIPSET_LOCKDOWN equivalent here.
-# TODO: If more platforms are able to enable CONFIG_INTEL_CHIPSET_LOCKDOWN in the future, have board config export APM_CNT and FIN_CODE and modify this script accordingly
 
 #include ash shell functions (TRACE requires it)
 . /etc/ash_functions