MIPS:DTS:Correct device id of pcie for Loongnon-2K

from Loongson-2K user manual know that Loongson-2K have two
pcie controller pcie0 and pcie1, pcie0 have four port named port0~port3
and pcie1 have 2 port named port0~port1. the device id of port0 is 7a19
in each pcie controller and others are 7a09.

Signed-off-by: Xiaochuan Mao <maoxiaochuan@loongson.cn>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>