ARM: OMAP: clock: cleanup CPUfreq leftovers

Now that we have OPP layer, and OMAP CPUfreq driver is using it, we no
longer need/use the clock framework code for filling up CPUfreq
tables.  Remove it.

Thanks to Russell King for pointing out the parts I missed under
plat-omap in the original version.

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>