KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL - reloaded

KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL - reloaded

This commit is filling out the blanks that were missed in the backport
26a0cd21bb76 ("KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL") due to lack
of different interfaces. 26a0cd21bb76 ("KVM/VMX: Allow direct access to
MSR_IA32_SPEC_CTRL") is basically an incomplet cherry-pick from
d28b387fb74da95d69d2615732f50cceb38e9a4d.

Also added the interception of MSR_IA32_SPEC_CTRL and
MSR_IA32_PRED_CMD in order for the get/set MSR handling to have a sense.

Orabug: 28069548

Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>