pci_host_generic: Simplify generic_pcie_translate_resource

Inline generic_pcie_translate_resource_common into its sole caller.
No functional change.

Reviewed by: tuexen
Differential Revision: https://reviews.freebsd.org/D44206

(cherry picked from commit 291079d0ebdd078840ccb27aaa5d286e03e2e7e6)