KVM: ia64: fix vmm_spin_{un}lock for !CONFIG_SMP

In the case of !CONFIG_SMP, raw_spinlock_t is empty and the spinlock functions
don't build.  Fix by defining spinlock functions for the uniprocessor case.

Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>