PCI: Remove add_align overwrite unrelated to size0

Commit 566f1dd5 ("PCI: Relax bridge window tail sizing rules")
relaxed bridge window tail alignment rule for the non-optional part
(size0, no add_size/add_align). The change, however, also overwrote
add_align, which is only related to case where optional size1 related
entry is added into realloc head.

Correct this by removing the add_align overwrite.

Link: https://lore.kernel.org/r/20241216175632.4175-2-ilpo.jarvinen@linux.intel.com


Fixes: 566f1dd5 ("PCI: Relax bridge window tail sizing rules")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Xiaochun Lee <lixc17@lenovo.com>