Remove obsolete tip referring to 2010 removal of TAP numbers.

Remove a tip describing the discouraged use of TAP numbers, and how
these numbers would be removed by mid-2010.

Change-Id: Iebe7e2e4a0f8e1f18a91d7935588dd9ced2b398d
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Reviewed-on: http://openocd.zylin.com/1862


Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>