ANDROID: block: backport the ability to specify max_dun_bytes

Backport a fix from the v7 inline crypto patchset which ensures that the
block layer knows the number of DUN bytes the inline encryption hardware
supports, so that hardware isn't used when it shouldn't be.

(This unfortunately means introducing some increasing long argument
lists; this was all already fixed up in later versions of the patchset.)

To avoid breaking the KMI for drivers, don't add a dun_bytes argument to
keyslot_manager_create() but rather allow drivers to call
keyslot_manager_set_max_dun_bytes() to override the default.  Also,
don't add dun_bytes as a new field in 'struct blk_crypto_key' but rather
pack it into the existing 'hash' field which is for block layer use.

Bug: 144046242
Bug: 153512828
Change-Id: I285f36557fb3eafc5f2f64727ef1740938b59dd7
Signed-off-by: Eric Biggers <ebiggers@google.com>