- it's 2020, there shouldn't be too many systems out there where SHA-1 is the
only available hash option, so its usefulness is limited
- OTOH testing configurations without SHA-2 reveal bugs that are not easy to
fix in a fully compatible way
So overall, the benefit/cost ratio is not good enough to justify keeping SHA-1
as a fallback option here.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>