KVM: x86: Move HF_GIF_MASK into "struct vcpu_svm" as "guest_gif"

Move HF_GIF_MASK out of the common "hflags" and into vcpu_svm.guest_gif.
GIF is an SVM-only concept and has should never be consulted outside of
SVM-specific code.

No functional change is intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Tested-by: Santosh Shukla <Santosh.Shukla@amd.com>
Link: https://lore.kernel.org/r/20221129193717.513824-5-mlevitsk@redhat.com


[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>