Use `combinations_with_replacement` for inputs
Use `combinations_with_replacement` for inputs

When generating combinations of values, `itertools.combinations` will
not allow inputs to be repeated. This is replaced so that cases where
input values match are generated, i.e. ("0", "0").

Signed-off-by: Werner Lewis <29432905d920442ec662bce9326f09fe8d37b3c0@arm.com>

Mbed-TLS/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls