Currently xenvm board/soc is configured to use GICv2 and there
is no clean way(without modifying the source code) to alter this
configuration to use GICv3.
Due to the increasing number of users wishing to use GICv3, add
a new configuration called xenvm_gicv3 that enables GICv3.
Create a Kconfig file and add a config XENVM_USE_GIC_V3 that,
if set, will cause SOC_XENVM to select GICv3 instead of GICv2.
Update documentation accordingly.
Take the opportunity to remove the unnecessary config options
from the defconfig files.
Signed-off-by: Michal Orzel <michal.orzel@arm.com>
176240c3c2
