KVM: Request setting of nmi_pending and sipi_vector

The final version of VCPU events in 2.6.33 will allow to skip
nmi_pending and sipi_vector on KVM_SET_VCPU_EVENTS. For now let's write
them unconditionally, which is unproblematic for upstream due to missing
SMP support. Future version which enable SMP will write them only on
reset.

Signed-off-by: Jan Kiszka <[email protected]>
Signed-off-by: Marcelo Tosatti <[email protected]>