iASL: Add check for predefined packages that are too large.

For predefined names that contain subpackages, check if each
subpackage is too large. (check for too small already exists.)
Update handling of PCI ID lists.

More of a style cleanup. if HwBuildPciList is to return a non-zero
status, it now deletes any partial ID list that has been constructed.
if it returns AE_OK, the caller is responsible for list deletion.
David Box.