dt-bindings: PCI: qcom: Fix description typo

Fix "based" typo in description.

Link: https://lore.kernel.org/r/e08b53be6cdf8d94a5a002d5b74c8a884b2ff3c6.1655100158.git.baruch@tkos.co.il


Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>