cmocka: Remove square root tests

This patch removes the square root test that has been successfully
converted from cmocka to ztest.

The ztest equivalent is in test/ztest/unit/math/advanced/functions/
test_square_root_ztest.c and was merged in PR #10764.

Ztest coverage for sqrt_int16.c:
- lines: 100% (27/27)
- funcs: 100% (1/1)

Code coverage testing did not reveal any regression.

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

Author: tmleman

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

@@ -1,10 +1,5 @@
 # SPDX-License-Identifier: BSD-3-Clause
 
-cmocka_test(square_root
-	square_root.c
-	${PROJECT_SOURCE_DIR}/src/math/sqrt_int16.c
-)
-
 cmocka_test(base_10_logarithm
 	base_10_logarithm.c
 	${PROJECT_SOURCE_DIR}/src/math/log_10.c