fix: KVM: x86/mmu: Make kvm_mmu_page definition and accessor internal-only (v5.9)

fix: KVM: x86/mmu: Make kvm_mmu_page definition and accessor internal-only (v5.9)

  commit 985ab2780164698ec6e7d73fad523d50449261dd
  Author: Sean Christopherson <sean.j.christopherson@intel.com>
  Date:   Mon Jun 22 13:20:32 2020 -0700

    KVM: x86/mmu: Make kvm_mmu_page definition and accessor internal-only

    Make 'struct kvm_mmu_page' MMU-only, nothing outside of the MMU should
    be poking into the gory details of shadow pages.

Change-Id: Ia5c1b9c49c2b00dad1d5b17c50c3dc730dafda20
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>