Add `_raw` function to P224K1

Modified the testing to use the generic fast reduction test function.

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/library/ecp_invasive.h b/library/ecp_invasive.h
index 78e0bcb..744945c 100644
--- a/library/ecp_invasive.h
+++ b/library/ecp_invasive.h
@@ -179,10 +179,11 @@
 int mbedtls_ecp_mod_p192k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 
 #endif /* MBEDTLS_ECP_DP_SECP192K1_ENABLED */
+
 #if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
 
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p224k1(mbedtls_mpi *N);
+int mbedtls_ecp_mod_p224k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 
 #endif /* MBEDTLS_ECP_DP_SECP224K1_ENABLED */