Add comment documenting introduced init_cb.
This solves the following warning when building the kernel documentation:

./include/linux/regulator/driver.h:435: warning: Function parameter or struct member 'init_cb' not described in 'regulator_desc'

Fixes: cfcdf395c21e ("regulator: core: add callback to perform runtime init")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/lkml/20241023155120.6c4fea20@canb.auug.org.au/
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 include/linux/regulator/driver.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index d2f4427504f081e28a0c5102f329eda48324f163..5b66caf1695db2ad27ed78cf6beb8ae55052b5b7 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -269,6 +269,11 @@ enum regulator_type {
  *               config but it cannot store it for later usage.
  *               Callback should return 0 on success or negative ERRNO
  *               indicating failure.
+ * @init_cb: Optional callback called after the parsing of init_data.
+ *           Allows the regulator to perform runtime init if necessary,
+ *           such as synching the regulator and the parsed constraints.
+ *           Callback should return 0 on success or negative ERRNO
+ *           indicating failure.
  * @id: Numerical identifier for the regulator.
  * @ops: Regulator operations table.
  * @irq: Interrupt number for the regulator.

-- 
2.45.2