doc: Add a new migration guide entry to display

Rename the pclk_pol and data_cmd-gpios propertys
to pclk-pol and data-cmd-gpios in the devicetree
and bindings of the display subsystem.

Signed-off-by: James Roy <[email protected]>

Author: rruuaanng

doc/releases/migration-guide-4.1.rst

@@ -154,6 +154,8 @@ Display
         ...
     };
 
+* Renamed the devicetree propertys ``pclk_pol`` and ``data_cmd-gpios``
+  to ``pclk-pol`` and ``data-cmd-gpios``.
 
 Enhanced Serial Peripheral Interface (eSPI)
 ===========================================