ARM: dts: bcm2711: Fix PCIe interrupts

The PCIe host bridge has two interrupt lines, one that goes towards it
PCIE_INTR2 second level interrupt controller and one for its MSI second
level interrupt controller. The first interrupt line is not currently
managed by the driver, which is why it was not a functional problem.

The interrupt-map property was also only listing the PCI_INTA interrupts
when there are also the INTB, C and D.

Reported-by: Jim Quinlan <jim2101024@gmail.com>
Fixes: d5c8dc0d ("ARM: dts: bcm2711: Enable PCIe controller")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>