tests/bench-slope: improve CPU frequency auto-detection
* configure.ac (gcry_cv_have_asm_volatile_memory): Check also if assembly memory barrier with input/output register is supported. * tests/bench-slope.c (auto_ghz_bench): Change to use base operation that takes two CPU cycles and unroll loop by 1024 operations.
CPU frequency is now correctly detected on AWS Graviton CPU (2.3Ghz).
- Signed-off-by: Jussi Kivilinna <firstname.lastname@example.org>