docs/core-api: Add integer power functions to the list

Some times integer power functions, such as int_sqrt(), are needed, but
there is nothing about them in the generated documentation.

Fill the gap by adding a reference to the corresponding exported functions.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/core-api/kernel-api.rst

@@ -141,6 +141,15 @@ Base 2 log and power Functions
 .. kernel-doc:: include/linux/log2.h
    :internal:
 
+Integer power Functions
+-----------------------
+
+.. kernel-doc:: lib/math/int_pow.c
+   :export:
+
+.. kernel-doc:: lib/math/int_sqrt.c
+   :export:
+
 Division Functions
 ------------------