awimage: remove leftover debug printf

For people who are wondering, IRA are my initials, not a political
statement of any kind ;)

Signed-off-by: Ithamar R. Adema <ithamar@upgrade-android.com>
awimage: cleanup header struct; fixup packing values

Signed-off-by: Ithamar R. Adema <ithamar@upgrade-android.com>
awimage: add -d option for only decrypting image

Signed-off-by: Ithamar R. Adema <ithamar@upgrade-android.com>
.gitignore: ignore decrypted images

Signed-off-by: Ithamar R. Adema <ithamar@upgrade-android.com>