docs: migration-guide-4.1: i2c: replace underscore with hyphen

migration guide entry after renaming device tree properties with hyphen
instead of underscore

Signed-off-by: Jilay Pandya <[email protected]>

Author: jilaypandya

doc/releases/migration-guide-4.1.rst

@@ -236,6 +236,7 @@ I2C
 ===
 
 * Renamed the ``compatible`` from ``nxp,imx-lpi2c`` to :dtcompatible:`nxp,lpi2c`.
+* Renamed the device tree property ``port_sel`` to ``port-sel```.
 
 I2S
 ===