dt-bindings: memory: mediatek: Add mt8188 smi binding

Add mt8188 smi supporting in the bindings.

In mt8188, there are two smi-common HW, one is for vdo(video output),
the other is for vpp(video processing pipe). They connect with different
smi-larbs, then some setting(bus_sel) is different. Differentiate them
with the compatible string.

Something like this:

IOMMU(VDO) IOMMU(VPP)
| |
SMI_COMMON_VDO SMI_COMMON_VPP
---------------- ----------------
| | ... | | ...
larb0 larb2 ... larb1 larb3 ...

Signed-off-by: Chengci.Xu <[e-mail]>
Reviewed-by: AngeloGioacchino Del Regno <[e-mail]>
Reviewed-by: Yong Wu <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml

···
   MediaTek SMI have two generations of HW architecture, here is the list
   which generation the SoCs use:
   generation 1: mt2701 and mt7623.
-  generation 2: mt2712, mt6779, mt8167, mt8173, mt8183, mt8186, mt8192 and mt8195.
+  generation 2: mt2712, mt6779, mt8167, mt8173, mt8183, mt8186, mt8188, mt8192 and mt8195.
 
   There's slight differences between the two SMI, for generation 2, the
   register which control the iommu port is at each larb's register base. But
···
           - mediatek,mt8173-smi-common
           - mediatek,mt8183-smi-common
           - mediatek,mt8186-smi-common
+          - mediatek,mt8188-smi-common-vdo
+          - mediatek,mt8188-smi-common-vpp
           - mediatek,mt8192-smi-common
           - mediatek,mt8195-smi-common-vdo
           - mediatek,mt8195-smi-common-vpp

Documentation/devicetree/bindings/memory-controllers/mediatek,smi-larb.yaml

···
           - mediatek,mt8173-smi-larb
           - mediatek,mt8183-smi-larb
           - mediatek,mt8186-smi-larb
+          - mediatek,mt8188-smi-larb
           - mediatek,mt8192-smi-larb
           - mediatek,mt8195-smi-larb
 
···
           enum:
             - mediatek,mt8183-smi-larb
             - mediatek,mt8186-smi-larb
+            - mediatek,mt8188-smi-larb
             - mediatek,mt8195-smi-larb
 
     then:
···
               - mediatek,mt2712-smi-larb
               - mediatek,mt6779-smi-larb
               - mediatek,mt8186-smi-larb
+              - mediatek,mt8188-smi-larb
               - mediatek,mt8192-smi-larb
               - mediatek,mt8195-smi-larb