KVM: selftests: arm64: Test that feature ID regs survive a reset

One of the expectations with feature ID registers is that their values
survive a vCPU reset. Start testing that.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240502233529.1958459-7-oliver.upton@linux.dev


Signed-off-by: Marc Zyngier <maz@kernel.org>