Document speed 11 for AOME_SET_CPUUSED & cpu-used

Speed 11 was added to real-time mode in
https://aomedia-review.googlesource.com/c/aom/+/169527.

Change-Id: I420fd9ae07fb4cf0ccbc782c4b36933cb54ac655

aom/aomcx.h

diff --git a/aom/aomcx.h b/aom/aomcx.h
index 3b7a806..dd8b94c 100644
--- a/aom/aomcx.h
+++ b/aom/aomcx.h
@@ -208,14 +208,14 @@
    * encoding process, values greater than 0 will increase encoder speed at
    * the expense of quality.
    *
-   * Valid range: 0..10. 0 runs the slowest, and 10 runs the fastest;
+   * Valid range: 0..11. 0 runs the slowest, and 11 runs the fastest;
    * quality improves as speed decreases (since more compression
    * possibilities are explored).
    *
-   * NOTE: 10 is only allowed in AOM_USAGE_REALTIME. In AOM_USAGE_GOOD_QUALITY
-   * and AOM_USAGE_ALL_INTRA, 9 is the highest allowed value. However,
-   * AOM_USAGE_GOOD_QUALITY treats 7..9 the same as 6. Also, AOM_USAGE_REALTIME
-   * treats 0..4 the same as 5.
+   * NOTE: 10 and 11 are only allowed in AOM_USAGE_REALTIME. In
+   * AOM_USAGE_GOOD_QUALITY and AOM_USAGE_ALL_INTRA, 9 is the highest allowed
+   * value. However, AOM_USAGE_GOOD_QUALITY treats 7..9 the same as 6. Also,
+   * AOM_USAGE_REALTIME treats 0..4 the same as 5.
    */
   AOME_SET_CPUUSED = 13,
 

av1/arg_defs.c

diff --git a/av1/arg_defs.c b/av1/arg_defs.c
index 35a2ab4..0575654 100644
--- a/av1/arg_defs.c
+++ b/av1/arg_defs.c
@@ -303,7 +303,7 @@
       ARG_DEF(NULL, "max-intra-rate", 1, "Max I-frame bitrate (pct)"),
 #if CONFIG_AV1_ENCODER
   .cpu_used_av1 = ARG_DEF(NULL, "cpu-used", 1,
-                          "Speed setting (0..6 in good mode, 5..10 in realtime "
+                          "Speed setting (0..6 in good mode, 5..11 in realtime "
                           "mode, 0..9 in all intra mode)"),
   .rowmtarg =
       ARG_DEF(NULL, "row-mt", 1,