cpufreq: ti-cpufreq: Add support for AM3517

The AM3517 only lists 600MHz @ 1.2V, but the register values for
0x4830A204 = 1b86 802f, it seems like am3517 might be a derivative
of the omap36 which OPPs would be OPP50 (300 MHz) and OPP100
(600 MHz).

This patch simply adds the am3517 to the compatible table
similar to a mix of the omap3430 and omap3430 structure.

Signed-off-by: Adam Ford <aford173@gmail.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Adam Ford <aford173@gmail.com>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>