armv8: layerscape: fix spin-table support

armv8: layerscape: fix spin-table support

Spin tables are broken with bootefi. This is because - in contrast to
the booti call chain - there is no call to smp_kick_all_cpus(). Due to
this missing call the secondary CPUs are never released from their "wait
for interrupt state", see secondary_boot_func() in lowlevel.S.

Originally, this "wait for interrupt" is there to make sure, the spin
table is cleared before the secondary cores read it for the first time.
But the boot flow for the layerscape architecture is different from
that. The CPUs are release from their BootROM _after_ U-Boot's
spin-table is cleared, see fsl_layerscape_wake_seconday_cores() in mp.c.
Thus, there is no need to wait for this interrupt and no need for
kicking all cores on cpu_release. An atomic 64bit write to the
spin-table and a "sev" is sufficient.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>