sparc/PCI: Add mem64 resource parsing for root bus

sparc/PCI: Add mem64 resource parsing for root bus

Found "no compatible bridge window" warning in boot log from T5-8.

pci 0000:00:01.0: can't claim BAR 15 [mem 0x100000000-0x4afffffff pref]: no compatible bridge window

That resource is above 4G, but does not get offset correctly as
root bus only report io and mem32.

pci_sun4v f02dbcfc: PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [io  0x804000000000-0x80400fffffff] (bus address [0x0000-0xfffffff])
pci_bus 0000:00: root bus resource [mem 0x800000000000-0x80007effffff] (bus address [0x00000000-0x7effffff])
pci_bus 0000:00: root bus resource [bus 00-77]

Add mem64 handling in pci_common for sparc, so we can have 64bit resource
registered for root bus at first.

After patch, will have:
pci_sun4v f02dbcfc: PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [io  0x804000000000-0x80400fffffff] (bus address [0x0000-0xfffffff])
pci_bus 0000:00: root bus resource [mem 0x800000000000-0x80007effffff] (bus address [0x00000000-0x7effffff])
pci_bus 0000:00: root bus resource [mem 0x800100000000-0x8007ffffffff] (bus address [0x100000000-0x7ffffffff])
pci_bus 0000:00: root bus resource [bus 00-77]

-v2: mem64_space should use mem_space.start as offset.
-v3: add IORESOURCE_MEM_64 flag
-v4: set name for mem64_space, otherwise /proc/iomem will have <bad> for name

Fixes: commit d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows")
Link: http://lkml.kernel.org/r/CAE9FiQU1gJY1LYrxs+ma5LCTEEe4xmtjRG0aXJ9K_Tsu+m9Wuw@mail.gmail.com
Reported-by: David Ahern <david.ahern@oracle.com>
Tested-by: David Ahern <david.ahern@oracle.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Orabug: 21826746

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
 arch/sparc/kernel/pci.c        |    7 ++++++-
 arch/sparc/kernel/pci_common.c |   17 +++++++++++++++--
 arch/sparc/kernel/pci_impl.h   |    1 +
 3 files changed, 22 insertions(+), 3 deletions(-)
(cherry picked from commit c9bf614a29d223f1c20bfb47668f817d963eb8a2)