ARM: dts: imx7d: Invert legacy PCI irq mapping

According to i.MX7D reference manual (Rev. 0.1, table 7-1, page 1221)
legacy PCI interrupt mapping is as follows:

 - PCIE INT A is IRQ 122
 - PCIE INT B is IRQ 123
 - PCIE INT C is IRQ 124
 - PCIE INT D is IRQ 125

Invert the mapping information in corresponding DT node to reflect
that.

Cc: yurovsky@gmail.com
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Fixes: a816d575 ("ARM: dts: imx7d: Add node for PCIe controller")
Signed-off-by: Shawn Guo <shawnguo@kernel.org>