Add support for hardware-wrapped encryption keys to the
dm-inlinecrypt target.

Introduce a new optional argument <key_type> to indicate
whether the provided key is a raw key or a hardware-wrapped
key. Based on this flag, the appropriate blk-crypto key type
is selected when initializing the key.

This allows dm-inlinecrypt to work with hardware that requires
keys to be wrapped and managed by the underlying inline
encryption engine.

Update the target argument parsing accordingly and pass the
key type to blk_crypto_init_key(). Documentation is also
updated to reflect the new parameter and usage.

Signed-off-by: Linlin Zhang <linlin.zhang@oss.qualcomm.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: e7f57d2c47e2 ("dm-inlinecrypt: add target for inline block device encryption")

This adds the admin-guide documentation for dm-inlinecrypt.

dm-inlinecrypt.rst is the guide to using dm-inlinecrypt.

Signed-off-by: Linlin Zhang <linlin.zhang@oss.qualcomm.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>