Update mbedtls_mpi_core_uint_le_mpi to new CT interface

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/bignum_core.h b/library/bignum_core.h
index 5432c80..e2d18e9 100644
--- a/library/bignum_core.h
+++ b/library/bignum_core.h
@@ -144,11 +144,11 @@
  * \param A_limbs  The number of limbs of \p A.
  *                 This must be at least 1.
  *
- * \return         1 if \p min is less than or equal to \p A, otherwise 0.
+ * \return         MBEDTLS_CT_TRUE if \p min is less than or equal to \p A, otherwise MBEDTLS_CT_FALSE.
  */
-unsigned mbedtls_mpi_core_uint_le_mpi(mbedtls_mpi_uint min,
-                                      const mbedtls_mpi_uint *A,
-                                      size_t A_limbs);
+mbedtls_ct_condition_t mbedtls_mpi_core_uint_le_mpi(mbedtls_mpi_uint min,
+                                                    const mbedtls_mpi_uint *A,
+                                                    size_t A_limbs);
 
 /**
  * \brief          Check if one unsigned MPI is less than another in constant