Change the ecp_mod_p224_raw to be testable

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index d42f093..a4b49ae 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -4575,7 +4575,8 @@
 #endif
 #if defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED)
 static int ecp_mod_p224(mbedtls_mpi *);
-static int ecp_mod_p224_raw(mbedtls_mpi_uint *Np, size_t Nn);
+MBEDTLS_STATIC_TESTABLE
+int ecp_mod_p224_raw(mbedtls_mpi_uint *Np, size_t Nn);
 #endif
 #if defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED)
 static int ecp_mod_p256(mbedtls_mpi *);
@@ -5057,7 +5058,8 @@
     return ret;
 }
 
-static int ecp_mod_p224_raw(mbedtls_mpi_uint *Np, size_t Nn)
+MBEDTLS_STATIC_TESTABLE
+int ecp_mod_p224_raw(mbedtls_mpi_uint *Np, size_t Nn)
 {
     if (Nn != 2 * ((224 + biL - 1) / biL)) {
         return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;