drivers: video: Update migration-guide

Rename the config CONFIG_VIDEO_HIMAX_HM01B0
to CONFIG_VIDEO_HM01B0

Signed-off-by: Kurt Eckhardt <kurte@rockisland.com>
Co-Authored-By: Alain Volmat <58030053+avolmat-st@users.noreply.github.com>

Author: KurtE

doc/releases/migration-guide-4.4.rst

@@ -113,6 +113,10 @@ Networking
   code cannot use POSIX APIs, then the relevant network API prefix needs to be added to the
   code calling a network API.
 
+Video
+*****
+
+* ``CONFIG_VIDEO_HIMAX_HM01B0`` has been renamed into :kconfig:option:`CONFIG_VIDEO_HM01B0`.
 Other subsystems
 ****************