Remove new bignum when not needed

New bignum modules are only needed when the new ecp_curves module is
present. Remove them when they are not needed to save code size.

Signed-off-by: Janos Follath <janos.follath@arm.com>
diff --git a/tests/suites/test_suite_bignum_random.function b/tests/suites/test_suite_bignum_random.function
index 6e533bc..b43b1e7 100644
--- a/tests/suites/test_suite_bignum_random.function
+++ b/tests/suites/test_suite_bignum_random.function
@@ -192,7 +192,7 @@
 }
 /* END_CASE */
 
-/* BEGIN_CASE */
+/* BEGIN_CASE depends_on:MBEDTLS_ECP_WITH_MPI_UINT */
 void mpi_mod_random_values(int min, char *max_hex, int rep)
 {
     /* Same RNG as in mpi_core_random_basic */
@@ -403,7 +403,7 @@
 }
 /* END_CASE */
 
-/* BEGIN_CASE */
+/* BEGIN_CASE depends_on:MBEDTLS_ECP_WITH_MPI_UINT */
 void mpi_mod_random_validation(int min, char *bound_hex,
                                int result_limbs_delta,
                                int expected_ret)