hv: vtd: remove global cache invalidation per vm

Cacheline is flushed on EPT entry change, no need to invalidate cache globally
when VM created per VM.

Tracked-On: #3607
Signed-off-by: Binbin Wu <binbin.wu@intel.com>
Reviewed-by: Anthony Xu <anthony.xu@intel.com>

hypervisor/arch/x86/vtd.c

@@ -1300,9 +1300,6 @@ int32_t move_pt_device(const struct iommu_domain *from_domain, struct iommu_doma
 
 void enable_iommu(void)
 {
-	if (!iommu_page_walk_coherent) {
-		cache_flush_invalidate_all();
-	}
 	do_action_for_iommus(dmar_enable);
 }