This patch adds a parser to the PCI routing tables returned by _PRT objects
of platform devices. The parsed result is a list of PRTMappingPackage
instances, each of which is a named tuple with the following fields:
* address: a dword with higher 16 bits being the function number and
lower 16 bits all 1's.
* pin: a byte representing the mapped pin.
* source: either a DeviceDecl of the device that allocates the interrupt
line, or the byte 0.
* source_index:
- If `source` is a DeviceDecl, this is the index of the interrupt
source within that device.
- If `source` is 0, this is the interrupt line connected to the pin.
Tracked-On: #6287
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
