Revert "ARM: dts: imx7d: Invert legacy PCI irq mapping"

This reverts commit 1c86c9dd.

That commit followed the reference manual but unfortunately the imx7d
manual is incorrect.

Tested with ath9k pcie card and confirmed internally.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Fixes: 1c86c9dd ("ARM: dts: imx7d: Invert legacy PCI irq mapping")
Signed-off-by: Shawn Guo <shawnguo@kernel.org>