of/pci: Add of_pci_dma_configure() to update DMA configuration
Add of_pci_dma_configure() to allow updating the DMA configuration of the
PCI device using the configuration from DT of the parent of the root bridge
device. Use the newly added APIs pci_get/put_host_bridge_device() for
implementing this.
[bhelgaas: fold in fix for host bridges with no parent OF device] Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> (AMD Seattle) Signed-off-by: Murali Karicheri <m-karicheri2@ti.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Rob Herring <robh+dt@kernel.org> Acked-by: Will Deacon <will.deacon@arm.com> CC: Joerg Roedel <joro@8bytes.org> CC: Grant Likely <grant.likely@linaro.org> CC: Russell King <linux@arm.linux.org.uk> CC: Arnd Bergmann <arnd@arndb.de>