KVM: MIPS: Fix a build error due to referencing not-yet-defined function

Hoist kvm_mips_comparecount_wakeup() above its only user,
kvm_arch_vcpu_create() to fix a compilation error due to referencing an
undefined function.

Fixes: d11dfed5 ("KVM: MIPS: Move all vcpu init code into kvm_arch_vcpu_create()")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>