Backport patch ("MIPS: ath79: drop _machine_restart again"), which is
required to support GPIO restart handler on ZTE MF286, broken due to
_machine_restart being restored in kernel accidentally, wich causes any
registered restart handlers to not execute, including one from
ath79-reset driver.
Signed-off-by: Lech Perczak <lech.perczak@gmail.com>