Better doc for AV1E_GET_LUMA_CDEF_STRENGTH

Change-Id: If7e63c085c6af31f43e7e8dfcdb34cce92e50634
(cherry picked from commit a08a85646841967861dd0dad04a985ebc16c9809)

aom/aomcx.h

diff --git a/aom/aomcx.h b/aom/aomcx.h
index 53bdc1e..a5db0a5 100644
--- a/aom/aomcx.h
+++ b/aom/aomcx.h
@@ -1513,8 +1513,9 @@
    */
   AV1E_SET_RATE_DISTRIBUTION_INFO = 161,
 
-  /*!\brief Codec control to get the CDEF strength for Y / luma plane.
-   * Returns an array of CDEF_MAX_STRENGTHS.
+  /*!\brief Codec control to get the CDEF strength for Y / luma plane,
+   * int * parameter.
+   * Returns an integer array of CDEF_MAX_STRENGTHS elements.
    */
   AV1E_GET_LUMA_CDEF_STRENGTH = 162,