libcamera: swstats_cpu: Update statsProcessFn() / processLine0() documentation

Update the documentation of the statsProcessFn() / processLine0() src[]
pointer argument to take into account that swstats_cpu may also be used
with planar input data or with non Bayer single plane input data.

The statsProcessFn typedef is private, so no documentation is generated
for it. Move the new updated src[] pointer argument documentation to
processLine0() so that it gets included in the generated docs.

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/libcamera/software_isp/swstats_cpu.cpp

@@ -72,6 +72,19 @@ namespace libcamera {
  * patternSize height == 1.
  * It'll process line 0 and 1 for input formats with patternSize height >= 2.
  * This function may only be called after a successful setWindow() call.
+ *
+ * This function takes an array of src pointers each pointing to a line in
+ * the source image.
+ *
+ * Bayer input data requires (patternSize_.height + 1) src pointers, with
+ * the middle element of the array pointing to the actual line being processed.
+ * Earlier element(s) will point to the previous line(s) and later element(s)
+ * to the next line(s). See the DebayerCpu::debayerFn documentation for details.
+ *
+ * Planar input data requires a src pointer for each plane, with src[0] pointing
+ * to the line in plane 0, etc.
+ *
+ * For non Bayer single plane input data only a single src pointer is required.
  */
 
 /**