Don't validate rc_param.max_depth

It's going to be removed from the API.

Bug: b/245539956
Change-Id: I2d9180120170b18a89d74df0695e5c4b37cca818
diff --git a/av1/ratectrl_qmode.cc b/av1/ratectrl_qmode.cc
index db92483..22068e5 100644
--- a/av1/ratectrl_qmode.cc
+++ b/av1/ratectrl_qmode.cc
@@ -249,11 +249,6 @@
                   << ") must be in the range [1, 7].";
     return { AOM_CODEC_INVALID_PARAM, error_message.str() };
   }
-  if (rc_param.max_depth < 1 || rc_param.max_depth > 5) {
-    error_message << "max_depth (" << rc_param.max_depth
-                  << ") must be in the range [1, 5].";
-    return { AOM_CODEC_INVALID_PARAM, error_message.str() };
-  }
   if (rc_param.base_q_index < 0 || rc_param.base_q_index > 255) {
     error_message << "base_q_index (" << rc_param.base_q_index
                   << ") must be in the range [0, 255].";
diff --git a/test/ratectrl_qmode_test.cc b/test/ratectrl_qmode_test.cc
index 71d858c..907319a 100644
--- a/test/ratectrl_qmode_test.cc
+++ b/test/ratectrl_qmode_test.cc
@@ -232,7 +232,6 @@
     rc_param_.min_gop_show_frame_count = 4;
     rc_param_.ref_frame_table_size = 7;
     rc_param_.max_ref_frames = 7;
-    rc_param_.max_depth = 5;
     rc_param_.base_q_index = 128;
     rc_param_.frame_height = kFrameHeight;
     rc_param_.frame_width = kFrameWidth;
@@ -928,13 +927,6 @@
               HasSubstr("max_ref_frames (8) must be in the range"));
 }
 
-TEST_F(RateControlQModeTest, TestInvalidMaxDepth) {
-  rc_param_.max_depth = 6;
-  Status status = AV1RateControlQMode().SetRcParam(rc_param_);
-  EXPECT_EQ(status.code, AOM_CODEC_INVALID_PARAM);
-  EXPECT_THAT(status.message, HasSubstr("max_depth (6) must be in the range"));
-}
-
 TEST_F(RateControlQModeTest, TestInvalidBaseQIndex) {
   rc_param_.base_q_index = 256;
   Status status = AV1RateControlQMode().SetRcParam(rc_param_);