Log Message:
u-boot-rockpro64: fix broken PCI config space handling:

- Program bus number into the ECAM decoder for each access
- Use type 1 PCI config cycles for config spaces behind bridge
- Add a platform specific hack to the synchronous exception handler
  to deal with PCI-e subsystem triggering data aborts when probing
  nonexistent PCI devices.
- properly delay after deasserting reset for downstream devices to
  have time to initialize.

Allows booting from PCI devices behind bridges and probing
devices other than 0:0:0 and 1:0:0.