Add a KUnit test suite for the Poly1305 functions. Most of its test
cases are instantiated from hash-test-template.h, which is also used by
the SHA-2 tests. A couple additional test cases are also included to
test edge cases specific to Poly1305.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250709200112.258500-5-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
