arm: configure interrupts to be in non-secure group1

arm: configure interrupts to be in non-secure group1

Xen uses non-secure group1 interrupts, however it doesn't configure the
GICv3 accordingly. Xen needs to set GICD_IGROUPR for SPIs and
GICR_IGROUPR0 for local interrupt to "1" to specify that interrupts
belong to group1. This is particularly important if the system has
GICD_CTLR.DS set, also see commit
7c9b973061b03af62734f613f6abec46c0dd4a88 in Linux.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Released-acked-by: Julien Grall <julien.grall@linaro.org>