Move spl_sqrt_floor dep to proper third_party directory

Bug: webrtc:8366
Change-Id: I326af5251dd88136dcc722e0ba1a2f9a8aebcf89
Reviewed-on: https://webrtc-review.googlesource.com/90405
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24205}
diff --git a/common_audio/BUILD.gn b/common_audio/BUILD.gn
index d6e860f..50bd0f4 100644
--- a/common_audio/BUILD.gn
+++ b/common_audio/BUILD.gn
@@ -94,10 +94,7 @@
   sources = []
   deps = []
   if (current_cpu == "arm") {
-    sources += [
-      "signal_processing/complex_bit_reverse_arm.S",
-      "signal_processing/spl_sqrt_floor_arm.S",
-    ]
+    sources += [ "signal_processing/complex_bit_reverse_arm.S" ]
 
     if (arm_version >= 7) {
       sources += [ "signal_processing/filter_ar_fast_q12_armv7.S" ]
@@ -170,7 +167,6 @@
       "signal_processing/include/spl_inl_mips.h",
       "signal_processing/min_max_operations_mips.c",
       "signal_processing/resample_by_2_mips.c",
-      "signal_processing/spl_sqrt_floor_mips.c",
     ]
     if (mips_dsp_rev > 0) {
       sources += [ "signal_processing/vector_scaling_operations_mips.c" ]
@@ -183,7 +179,6 @@
     sources += [
       "signal_processing/complex_bit_reverse.c",
       "signal_processing/filter_ar_fast_q12.c",
-      "signal_processing/spl_sqrt_floor.c",
     ]
   }
 
@@ -199,6 +194,7 @@
     "../system_wrappers",
     "../system_wrappers:cpu_features_api",
     "third_party/fft4g:fft4g",
+    "third_party/spl_sqrt_floor",
   ]
 }