PCI: hisi: Fix DT binding (hisi-pcie-almost-ecam)

The "hisilicon,pcie-almost-ecam" binding goes against the usual DT
conventions, and is non-sensical in that it describes the IP based on
what it isn't.  Fix the DT binding with "hisilicon,hip06-pcie-ecam"
and "hisilicon,hip07-pcie-ecam".

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>