add armv7a_cache handlers

add armv7a_cache handlers

This patch introduces, new command set and handlers for l1 and l2x caches.

Patch set 10 folded the following changes into this one:

Ib1a2a1fc1b929dc49532ac13a78e8eb796ab4415
If8d87a03281d0f4ad402909998e7834eb4837e79
I0749f129fa74e04f4e9c20d143a744f09ef750d8

Change-Id: I849f4d1f20610087885eeddefa81d976f77cf199
Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: Matthias Welwarsky <matthias@welwarsky.de>
Reviewed-on: http://openocd.zylin.com/2800
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>