Move fields around to have fewer accesses outside the 128-element Thumb
direct access window.
In psa_hkdf_key_derivation_t, move the large fields (output_block, prk,
hmac) after the state bit-fields. Experimentally, it's slightly better
to put hmac last.
Other operations structures don't go outside the window, at least when not
considering nested structures.
Results (arm-none-eabi-gcc 7.3.1, build_arm_none_eabi_gcc_m0plus build):
library/psa_crypto.o: 16510 -> 16434 (diff: 76)
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
e3d9c9d99b