clk: ti: omap5: Add missing AESS clock

Looks like we're missing AESS clock for omap5. This is similar to what
omap4 has.

Cc: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Matthijs van Duin <matthijsvanduin@gmail.com>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>