PCI: endpoint: pci-epf-vntb: Clean up kernel_doc warning

Cleanup warning found by scripts/kernel-doc.

Consolidate terms:

- host, host1 to HOST
- vhost, vHost, Vhost, VHOST2 to VHOST

Link: https://lore.kernel.org/r/20221102141014.1025893-2-Frank.Li@nxp.com


Signed-off-by: Frank Li <frank.li@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>