KVM: VMX: Enumerate EPT Violation #VE support in /proc/cpuinfo

Don't suppress printing EPT_VIOLATION_VE in /proc/cpuinfo, knowing whether
or not KVM_INTEL_PROVE_VE actually does anything is extremely valuable.
A privileged user can get at the information by reading the raw MSR, but
the whole point of the VMX flags is to avoid needing to glean information
from raw MSR reads.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20240518000430.1118488-9-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>