Allow BLKIOMIN and BLKALIGNOFF ioctls to the super device in fastbootd.

These ioctls are similar to BLKGETSIZE64; they return benign information
about the partition's alignment, and are used by liblp to optimally
align dynamic partition extents.

The system_block_device is included here because on retrofit devices,
the "super" partition is mapped to the system partition.

Bug: 116802789
Test: fastboot flashall
Change-Id: I38282904828105cf5f16ce9d4b5884d2b0e89d38