clk: ti: add omap3 legacy clock data

Introduces omap3 legacy clock data under clock driver. The clock data
is also in new format, which makes it possible to get rid of the
clk-private.h header. This patch also introduces SoC specific init
functions that shall be called from the low level init.

The data format used in this file has two possible evolution paths;
it can either be removed completely once no longer needed, or it will
be possible to retain the format and modify the TI clock driver to be
a loadable module at some point. The actual path to be followed
will be decided later.

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