pci: Update dm_pci_bus_to_virt() parameters

Add mask parameter and reorder length parameter to match the other PCI
address conversion functions. Using PCI_REGION_TYPE as the mask gives
the old behaviour.

It's converted from a macro to an inline function as the length
parameter is now used twice, but should only be calculated once.

Signed-off-by: Andrew Scull <ascull@google.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>