KVM: x86: Delete duplicate documentation for KVM_X86_SET_MSR_FILTER

Two copies of KVM_X86_SET_MSR_FILTER somehow managed to make it's way
into the documentation.  Remove one copy and merge the difference from
the removed copy into the copy that's being kept.

Fixes: fd49e8ee ("Merge branch 'kvm-sev-cgroup' into HEAD")
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Link: https://lore.kernel.org/r/20220712001045.2364298-2-aaronlewis@google.com


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