Xenial SRU - [Hyper-V] Missing PCI patches breaking SR-IOV hot remove

[Tim Gardner]

These are the same clean cherry-picks as Yakkety, but with slightly
different context, hence the second set.

https://bugs.launchpad.net/bugs/1670518

[PATCH 1/4] PCI: hv: Fix hv_pci_remove() for hot-remove
[PATCH 2/4] PCI: hv: Delete the device earlier from hbus->children
[PATCH 3/4] PCI: hv: Make unnecessarily global IRQ masking functions
[PATCH 4/4] PCI: hv: Allocate physically contiguous hypercall params

rtg