CLK: TI: add autoidle support

TI clk driver now routes some of the basic clocks through own
registration routine to allow autoidle support. This routine just
checks a couple of device node properties and adds autoidle support
if required, and just passes the registration forward to basic clocks.

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