Apply naming conventions

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/library/ecp_invasive.h b/library/ecp_invasive.h
index 8e321ab..7adbe7e 100644
--- a/library/ecp_invasive.h
+++ b/library/ecp_invasive.h
@@ -119,7 +119,7 @@
 #if defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED)
 
 MBEDTLS_STATIC_TESTABLE
-int ecp_mod_p256_raw(mbedtls_mpi_uint *Np, size_t Nn);
+int mbedtls_ecp_mod_p256_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 
 #endif