mainboard: Clean up boot_option/reboot_bits in cmos.layout

Since commit 3bfd7cc (drivers/pc80: Rework normal / fallback selector
code) the reboot counter stored in `reboot_bits` isn't reset on a reboot
with `boot_option = 1` any more. Hence, with SKIP_MAX_REBOOT_CNT_CLEAR
enabled, later stages (e.g. payload, OS) have to clear the counter too,
when they want to switch to normal boot. So change the bits to (h)ex
instead of (r)eserved.

To clarify their meaning, rename `reboot_bits` to `reboot_counter`. Also
remove all occurences of the obsolete `last_boot` bit that have sneaked
in again since 24391321 (mainboard: Remove last_boot NVRAM option).

Change-Id: Ib3fc38115ce951b75374e0d1347798b23db7243c
Signed-off-by: Nico Huber <>
Tested-by: build bot (Jenkins)
Reviewed-by: Timothy Pearson <>
Reviewed-by: York Yang <>
Reviewed-by: Paul Menzel <>
177 files changed