PCI: aardvark: Size bridges before resources allocation
The PCIE I/O and MEM resource allocation mechanism is that root bus
goes through the following steps:
1. Check PCI bridges' range and computes I/O and Mem base/limits.
2. Sort all subordinate devices I/O and MEM resource requirements and
allocate the resources and writes/updates subordinate devices'
requirements to PCI bridges I/O and Mem MEM/limits registers.
Currently, PCI Aardvark driver only handles the second step and lacks
the first step, so there is an I/O and MEM resource allocation failure
when using a PCI switch. This commit fixes that by sizing bridges
before doing the resource allocation.