Add `_raw` function to P192K1

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 68187ac..78e0bcb 100644
--- a/library/ecp_invasive.h
+++ b/library/ecp_invasive.h
@@ -176,7 +176,7 @@
  * with R = 2^32 + 2^12 + 2^8 + 2^7 + 2^6 + 2^3 + 1 = 0x0100001119
  */
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p192k1(mbedtls_mpi *N);
+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)