Merge branch 'pci/endpoint'

- Convert the endpoint doorbell test to use a threaded IRQ to fix a
  'sleeping while atomic' issue (Bhanu Seshu Kumar Valluri)

- Add endpoint VNTB MSI doorbell support to reduce latency between host and
  endpoint (Frank Li)

* pci/endpoint:
  PCI: endpoint: pci-epf-vntb: Add MSI doorbell support
  PCI: endpoint: Add pci_epf_assign_bar_space() API
  PCI: endpoint: Add pci_epf_get_required_bar_size() helper
  PCI: endpoint: Rename 'epf_bar::aligned_size' to 'epf_bar:mem_size'
  PCI: endpoint: pci-epf-test: Fix sleeping function being called from atomic context