tests: Fix testsuite after the FIPS adjustments.

* tests/benchmark.c (ecc_bench): Avoid not approved curves in FIPS.
* tests/curves.c (check_get_params): Skip Brainpool curves in FIPS.
* tests/keygen.c (check_dsa_keys): Generate 2048 and 3072 bits keys.
(check_ecc_keys): Skip Ed25519 in FIPS mode.
* tests/random.c (main): Don't switch DRBG in FIPS mode.
* tests/t-ed25519.c (main): Ed25519 isn't supported in FIPS mode.
* tests/t-kdf.c (check_openpgp): Skip vectors using md5 in FIPS.
* tests/t-mpi-point.c (context_param): Skip P-192 and Ed25519 in FIPS.
(main): Skip math tests that use P-192 and Ed25519 in FIPS.

Fix the testsuite to make it pass after the FIPS adjustmens.
This consists mostly of disabling the tests that use not approved
curves and algorithms as well as increasing the keysizes.

Additional changes by wk:

• Removed changes already done with commit e40939b. The original patch had these chnages:
  • tests/fips186-dsa.c (main): Merely suggest a future improvement.
  • tests/pubkey.c (get_dsa_key_*new): Increase keysizes. (check_run): Skip tests with small domain in FIPS. (main): Skip Ed25519 sample key test in FIPS. Noet that get_dsa_key_fips186_with_seed_new was not changed from 1024 to 3072 but to 2048 bit.
• Return with 77 (skip) from t-ed25519.c in FIPS mode.
• Some code style changes.

• Signed-off-by: Werner Koch <wk@gnupg.org>