docs: update references to the device io book

While converting the deviceiobook from DocBook to RST, dangling
references were left behind. This commit updates all remaining
references to the new location. SeongJae Park improved the ko_KR
translation.

Fixes: 8a8a602f ("docs: Convert the deviceio template to RST")
Signed-off-by: Helmut Grohne <h.grohne@intenta.de>
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>