ARM: OMAP3: clock data: cleanup AM3[35]x SoC detection

Use the more generic SoC family soc_is_am35xx() instead of the specific
cpu_is_omap3517() (which is being removed.)

Acked-by: Vaibhav Hiremath <hvaibhav@ti.com>
Tested-by: Vaibhav Hiremath <hvaibhav@ti.com>
Tested-by: Mark A. Greer <mgreer@animalcreek.com>
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>