staging: omap-thermal: remove freq_clip table

The API exposed by cpu cooling does not need any freq clip
table anymore. Now the cpu cooling device is smart enough
to build its own table.

For this reason, this patch removes all the code that is
generating a freq clip table and also removes all references
in data structures regarding freq clip table.

Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>