KVM: svm: set/clear all DR intercepts in one swoop

Unlike other intercepts, debug register intercepts will be modified
in hot paths if the guest OS is bad or otherwise gets tricked into
doing so.

Avoid calling recalc_intercepts 16 times for debug registers.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --cc arch/x86/kvm/svm.c
Simple merge