KVM: arm/arm64: Allow GICv2 to supply a uaccess register function
We are about to differentiate between writes from a VCPU and from
userspace to the GIC's GICD_ISACTIVER and GICD_ICACTIVER registers due
to different synchronization requirements.
Expand the macro to define a register description for the GIC to take
uaccess functions as well.
Signed-off-by: Christoffer Dall <cdall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>