FROMLIST: KVM: arm64: vgic-init: Remove vgic_ready() macro

It is now used only within kvm_vgic_map_resources(). vgic_dist::ready
is already written directly by this function, so it is clearer to
bypass the macro for reads as well.

Bug: 395485007
Bug: 357781595
Link: https://lore.kernel.org/all/20250624092256.1105524-2-keirf@google.com/



Change-Id: I924de8c4a02ed5d3af39b798af12d015d577d2f7
Signed-off-by: Keir Fraser <keirf@google.com>