Use SHA512 directly calculated over image with the ED25519 signature.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>

The commit add support for passing storage device address space
to hash calculation functions, which allows to use hardware
accelerated hash calculation on storage.
This feature only works when image encryption is not enabled
and all slots are defined within internal storage of device.

The feature is enabled using Kconfig option
 CONFIG_BOOT_IMG_HASH_DIRECTLY_ON_STORAGE

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>

The commit adds support for PureEdDSA, which validates signature
of image rather than hash. This is most secure, available, ED25519
usage in MCUboot, but due to requirement of PureEdDSA to be able
to calculate signature at whole message at once, here image,
it only works on setups where entire image can be mapped to
device address space, so that PSA functions calculating the
signature can see the whole image at once.

This option is enabled with Kconfig option:
 CONFIG_BOOT_SIGNATURE_TYPE_PURE
when the ED25519 signature type is already selected.

Note that the option will enable SHA512 for calculating public
key hash.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>