xen/arm: if direct-map domain use native addresses for GICv3

xen/arm: if direct-map domain use native addresses for GICv3

Today we use native addresses to map the GICv3 for Dom0 and fixed
addresses for DomUs.

This patch changes the behavior so that native addresses are used for
all domain which is using the host memory layout

Considering that DOM0 may not always be directly mapped in the future,
this patch introduces a new helper "domain_use_host_layout()" that
wraps both two check "is_domain_direct_mapped(d) || is_hardware_domain(d)"
for more flexible usage.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>