arm64: dts: ti: k3-am65-main: Add device_type to pcie*_rc nodes

This is demanded by the parent binding of ti,am654-pcie-rc, see
Documentation/devicetree/bindings/pci/designware-pcie.txt.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Kishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/881dfd6c75423efce1d10261909939cd5ef19937.1613071976.git.jan.kiszka@siemens.com