dt-bindings: PCI: mediatek-gen3: Add support for MT8188 and MT8195

MT8188 and MT8195 are ARM platform SoCs with the same PCIe IP as MT8192.

Also add new clock name "peri_mem" since the MT8188 and MT8195 use clock
"peri_mem" instead of "top_133m".

Link: https://lore.kernel.org/r/20220802120624.19258-1-jianjun.wang@mediatek.com


Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>