tcl/target/armada370: remove useless 'init' command

tcl/target/armada370: remove useless 'init' command

As the comment states, the 'init' command is issued before the
command 'dap apsel', otherwise it fails.
This dependency has been already fixed in commit e48690cb26e4
("target/arm_adi_v5: allow commands apsel and apcsw during init
phase"), so the command 'dap apsel' can now be issued directly.

Remove both the unneeded 'init' command and the comment that
documents and justify its presence.

Change-Id: I50f0a820fa7ead6f5a3bd9cc5180d521070822c9
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5786
Tested-by: jenkins