flash/kinetis: use coherent indentation in struct initialization

Keep using the same indentation rules while initializing struct
command_registration.

Change-Id: Ie69d9d6a786e1ef0abbcfd3eef89a61206238ebe
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5014


Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Tested-by: jenkins