clk: ti: add API for creating aliases automatically for simple clock types

This API generates clock aliases automatically for simple clock types
(fixed-clock, fixed-factor-clock), so that we don't need to add the data
for these statically into tables. Shall be called from the SoC specific
clock init.

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