KVM: MIPS: Setup VZ emulation? directly from kvm_mips_init()

Invoke kvm_mips_emulation_init() directly from kvm_mips_init() instead
of bouncing through kvm_init()=>kvm_arch_init().  Functionally, this is
a glorified nop as invoking kvm_arch_init() is the very first action
performed by kvm_init().

Emptying kvm_arch_init() will allow dropping the hook entirely once all
architecture implementations are nops.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221130230934.1014142-23-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>