dt-bindings: imx6q-pcie: Fix clock names for imx6sx and imx8mq

Originally as it was defined the legacy bindings the pcie_inbound_axi and
pcie_aux clock names were supposed to be used in the fsl,imx6sx-pcie and
fsl,imx8mq-pcie devices respectively. But the bindings conversion has been
incorrectly so now the fourth clock name is defined as "pcie_inbound_axi
for imx6sx-pcie, pcie_aux for imx8mq-pcie", which is completely wrong.
Let's fix that by conditionally apply the clock-names constraints based on
the compatible string content.

Link: https://lore.kernel.org/r/20221113191301.5526-2-Sergey.Semin@baikalelectronics.ru


Fixes: 751ca492 ("dt-bindings: PCI: imx6: convert the imx pcie controller to dtschema")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Alexander Stein <alexander.stein@ew.tq-group.com>