clk: ti: generalize the init sequence of clk_hw_omap clocks

Add a generic API for initializing clocks of clk_hw_omap type clocks,
and convert the whole TI clock driver suite to use this for registering
the clocks. Also, get rid of the now redundant API for adding the clocks
to the OMAP HW clocks list; instead this is used directly from the
register API.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Keerthy <j-keerthy@ti.com>