[sw/tests] Move sca unittests.

Move sca unittests next to their respective target location.

Signed-off-by: Miguel Osorio <miguelosorio@google.com>
diff --git a/sw/device/sca/lib/meson.build b/sw/device/sca/lib/meson.build
index 8da4052..251aeed 100644
--- a/sw/device/sca/lib/meson.build
+++ b/sw/device/sca/lib/meson.build
@@ -26,6 +26,20 @@
   ),
 )
 
+test('sca_lib_prng_unittest', executable(
+    'sca_lib_prng_unittest',
+    sources: [
+      'prng.c',
+      'prng_unittest.cc',
+    ],
+    dependencies: [
+      sw_vendor_gtest,
+    ],
+    native: true,
+  ),
+  suite: 'sca',
+)
+
 sw_sca_lib_simple_serial = declare_dependency(
   link_with: static_library(
     'lib_simple_serial',
diff --git a/sw/device/sca/lib/prng.h b/sw/device/sca/lib/prng.h
index 70bc14a..63f20c0 100644
--- a/sw/device/sca/lib/prng.h
+++ b/sw/device/sca/lib/prng.h
@@ -6,6 +6,7 @@
 #define OPENTITAN_SW_DEVICE_SCA_LIB_PRNG_H_
 
 #include <stddef.h>
+#include <stdint.h>
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/sw/device/tests/sca/sca_prng_unittest.cc b/sw/device/sca/lib/prng_unittest.cc
similarity index 99%
rename from sw/device/tests/sca/sca_prng_unittest.cc
rename to sw/device/sca/lib/prng_unittest.cc
index 70df563..a46f02e 100644
--- a/sw/device/tests/sca/sca_prng_unittest.cc
+++ b/sw/device/sca/lib/prng_unittest.cc
@@ -2,10 +2,12 @@
 // Licensed under the Apache License, Version 2.0, see LICENSE for details.
 // SPDX-License-Identifier: Apache-2.0
 
+#include "sw/device/sca/lib/prng.h"
+
 #include <algorithm>
+
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
-#include "sw/device/sca/lib/prng.h"
 
 namespace sca_prng_unittest {
 namespace {
diff --git a/sw/device/tests/meson.build b/sw/device/tests/meson.build
index 7177252..f07c56a 100644
--- a/sw/device/tests/meson.build
+++ b/sw/device/tests/meson.build
@@ -27,7 +27,6 @@
 
 subdir('dif')
 subdir('runtime')
-subdir('sca')
 subdir('sim_dv')
 subdir('otbn')
 
diff --git a/sw/device/tests/sca/meson.build b/sw/device/tests/sca/meson.build
deleted file mode 100644
index ebce66e..0000000
--- a/sw/device/tests/sca/meson.build
+++ /dev/null
@@ -1,15 +0,0 @@
-# Copyright lowRISC contributors.
-# Licensed under the Apache License, Version 2.0, see LICENSE for details.
-# SPDX-License-Identifier: Apache-2.0
-
-test('sca_prng_unittest', executable(
-  'sca_prng_unittest',
-  sources: [
-    meson.source_root() / 'sw/device/sca/lib/prng.c',
-    'sca_prng_unittest.cc',
-  ],
-  dependencies: [
-    sw_vendor_gtest,
-  ],
-  native: true,
-))