cmocka: Remove greatest common divisor tests

This patch removes tests that have been successfully converted to the
new framework (from cmock to ztest).

Code coverage testing did not reveal any regression.

CMock stats for number.c
- lines: 80.4 % (45/56)
- funcs: 83.3 % (5/6)
- branches: 78.1 % (25/32)

Ztest stats for number.c
- lines: 83.6 % (46/55)
- funcs: 83.3 % (5/6)
- branches: 78.9 % (30/38)

Additionally, information about the source of the original code and its
author has been added to the new version of tests.

Signed-off-by: Tomasz Leman <tomasz.m.leman@intel.com>

Author: tmleman

test/cmocka/src/math/numbers/CMakeLists.txt

@@ -1,10 +1,5 @@
 # SPDX-License-Identifier: BSD-3-Clause
 
-cmocka_test(gcd
-	gcd.c
-	${PROJECT_SOURCE_DIR}/src/math/numbers.c
-)
-
 cmocka_test(find_equal_int16
 	find_equal_int16.c
 	${PROJECT_SOURCE_DIR}/src/math/numbers.c

test/cmocka/src/math/numbers/gcd.c

@@ -6,6 +6,9 @@
 // generative artificial intelligence solutions.
 //
 // Converted from CMock to Ztest
+// Original tests from test/cmocka/src/math/numbers/gcd.c:
+// Author: Marcin Maka <marcin.maka@linux.intel.com>
+//         Janusz Jankowski <janusz.jankowski@linux.intel.com>
 
 #include <zephyr/ztest.h>
 #include <sof/math/numbers.h>