ARM: OMAP2+: clock: add support for specific CM ops to ti_clk_ll_ops

Clock driver requires access to some CM API functions once the code
is being moved under the clock driver from the platform directory.
Gate type clock requires access to cm_wait_module_ready and
cm_split_idlest_reg functions, which are both used for waiting until
the module being clocked has been successfully activated. These CM
APIs are now exported through the ti_clk_ll_ops struct.

Signed-off-by: Tero Kristo <t-kristo@ti.com>