CLK: ti: add support for ti divider-clock

This patch adds support for TI divider clock binding, which simply uses
the basic clock divider to provide the features needed.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>