dt-bindings: i2c: mpc: Make each example a separate entry

Each independent example should be a separate entry. This allows for
'interrupts' to have different cell sizes.

Signed-off-by: Rob Herring <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

Documentation/devicetree/bindings/i2c/i2c-mpc.yaml

···
         clock-frequency = <100000>;
     };
 
+  - |
     /* MPC5200B based board */
     i2c@3d00 {
         #address-cells = <1>;
···
         fsl,preserve-clocking;
     };
 
+  - |
     /* MPC8544 base board */
     i2c@3100 {
         #address-cells = <1>;