KVM: arm64: Advertise FGT2 registers to userspace

While a guest is able to use the FEAT_FGT2 registers, we're missing
them being exposed to userspace. Add them to the (very long) list.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250714122634.3334816-9-maz@kernel.org


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>