The current A/B switching preparatory altbootcmd is confusing
to users, replace it with plain 'run bootcmd' which can be
replaced by proper A/B switching altbootcmd when the matching
updater is added on top of the platform. By default, keep the
boot counter incrementing, but do not do any A/B partition
switching.
Signed-off-by: Marek Vasut <marex@denx.de>