pci: msm: Remove RC and EP config space shadow save and restore

All endpoints and bridge are performing their config space save
and restore. Hence root complex driver does not need to perform
the same on behalf of them. For root complex use PCI framework
provided APIs to perform RC config space save and restore. Save
golden copy of the RC config space upon enumeration and use it
to restore RC config space in case of link down. Get rid of all
custom APIs for saving, restoring and dumping of RC and EP config
space entries.

Change-Id: I466e26aaaee0ae317323aae0c535c3319f95e681
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>