of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses

Many other resource flag parsers already add this flag when the input
has bits 24 & 25 set, so update this one to do the same.

Some devices (like virtio-net) have more than one memory resource
(like MMIO32 and MMIO64) and without this flag it would be needed to
verify the address range to know which one is which.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Link: https://lore.kernel.org/r/20210415180050.373791-1-leobras.c@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>