ARM64: 7648/1: pci: Allow passing per-controller private data

ARM64: 7648/1: pci: Allow passing per-controller private data

In order to allow drivers to specify private data for each controller,
this commit adds a private_data field to the struct hw_pci. This field
is an array of nr_controllers pointers that will be used to initialize
the private_data field of the corresponding controller's pci_sys_data
structure.

vidyas: make the similar change for ARM64
based on upstream commit 352af7d4dd90bac3640ad2383e4e9f332d3a4537

Bug 200012096

Change-Id: I5bdc33dbb2cf543e69d4c67154d3d0c64843e7af
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Reviewed-on: http://git-master/r/433159
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>