KVM: x86: Unconditionally call x86 ops that are always implemented

KVM: x86: Unconditionally call x86 ops that are always implemented

Remove a few stale checks for non-NULL ops now that the ops in question
are implemented by both VMX and SVM.

Note, this is **not** stable material, the Fixes tags are there purely
to show when a particular op was first supported by both VMX and SVM.

Fixes: 1562b96f86af ("kvm/svm: Setup MCG_CAP on AMD properly")
Fixes: 2424f5118fc5 ("KVM: X86: Provide a capability to disable PAUSE intercepts")
Fixes: 8670052777a8 ("svm: Implements update_pi_irte hook to setup posted interrupt")
Cc: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>