doc: releases: 4.1: announce switch to video_bits_per_pixel()

The previous commit introduces video_bits_per_pixel() and converts
all invocation relying on video_pix_fmt_bpp(), 3rd-party users will
need to do the same on their code, and this is not a 100% drop-in API,
so better document it on the release notes.

Signed-off-by: Josuah Demangeon <[email protected]>

Author: josuah

doc/releases/migration-guide-4.1.rst

@@ -354,6 +354,11 @@ Video
   The new ``video-controls.h`` source now contains description of each control ID to help
   disambiguating.
 
+* The ``video_pix_fmt_bpp()`` function was returning a byte count, this got replaced by
+  ``video_bits_per_pixel()`` which return a bit count. For instance, invocations such as
+  ``pitch = width * video_pix_fmt_bpp(pixfmt)`` needs to be replaced by an equivalent
+  ``pitch = width * video_bits_per_pixel(pixfmt) / BITS_PER_BYTE``.
+
 Watchdog
 ========
 

doc/releases/release-notes-4.1.rst

@@ -300,6 +300,9 @@ Drivers and Sensors
   * Changed :file:`include/zephyr/drivers/video-controls.h` to have control IDs (CIDs) matching
     those present in the Linux kernel.
 
+  * Changed ``video_pix_fmt_bpp()`` returning the byte count and only supports 8-bit depth,
+    into ``video_bits_per_pixel()`` returning the bit count and supports any color depth.
+
 * Watchdog
 
   * Added :kconfig:option:`CONFIG_HAS_WDT_NO_CALLBACKS` which drivers select when they do not support