OvmfPkg/PciHostBridgeLib: consolidate #includes and INF file sections

OvmfPkg/PciHostBridgeLib: consolidate #includes and INF file sections

- In every C file, list every necessary public #include individually, with
  an example identifier that's actually consumed.

- Place all public #includes first, all module-private #includes second.
  Separate them with a single empty line. Keep each section sorted in
  itself.

- Sort all sections in the INF file, except [Defines].

- Add unlisted lib classes.

- Remove unnecessary #include directives, add unlisted #include
  directives.

Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Julien Grall <julien@xen.org>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2122
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20210526201446.12554-29-lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>