This patch add gicv3 support to uboot armv8 platform.
Changes for v2:
- rename arm/cpu/armv8/gic.S with arm/lib/gic_64.S
- move smp_kick_all_cpus() from gic.S to start.S, it would be
implementation dependent.
- Each core initialize it's own ReDistributor instead of master
initializeing all ReDistributors. This is advised by arnab.basu
<arnab.basu@freescale.com>.
Signed-off-by: David Feng <fenghua@phytium.com.cn>
