lib/crypto: tests: Introduce CRYPTO_LIB_ENABLE_ALL_FOR_KUNIT

lib/crypto: tests: Introduce CRYPTO_LIB_ENABLE_ALL_FOR_KUNIT

For kunit.py to run all the crypto library tests when passed the
--alltests option, tools/testing/kunit/configs/all_tests.config needs to
enable options that satisfy the test dependencies.

This is the same as what lib/crypto/.kunitconfig already does.
However, the strategy that lib/crypto/.kunitconfig currently uses to
select all the hidden library options isn't going to scale up well when
it needs to be repeated in two places.

Instead let's go ahead and introduce an option
CRYPTO_LIB_ENABLE_ALL_FOR_KUNIT that depends on KUNIT and selects all
the crypto library options that have corresponding KUnit tests.

Update lib/crypto/.kunitconfig to use this option.

Link: https://lore.kernel.org/r/20260314035927.51351-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>