Linux/Aarch64: support SHA acceleration detection with older libc
On Linux on aarch64 (64-bit ARMv8) processors, we use getauxval() to detect
whether the runtime environment supports SHA-256 or SHA-512 acceleration.
Some libc do not define the necessary HWCAP_xxx constants to analyze the
result of getauxval(), either because they don't bother or because they're
too old to recognize the values we need (for example, HWCAP_SHA2 appeared in
Glibc 2.24 and HWCAP_SHA512 appeared in Glibc 2.27). In such cases, assume
that the values are the same as in the kernel ABI and define the constants
manually.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
