block: Implemented ROW v4 I/O scheduler

Change-Id: Id0007c91e99d06259821dbe8fd39fa5f895519fa
Signed-off-by: zwliew <zhaoweiliew@gmail.com>
block: row: add magic values

Change-Id: I71fae7056bed3eb5a0e0995d1a0c88e908def6aa
Signed-off-by: zwliew <zhaoweiliew@gmail.com>