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>