OMAP2/3 clock: use standard set_rate fn in omap2_clk_arch_init()

Use the standard clk_set_rate() function in omap2_clk_arch_init()
rather than omap2_select_table_rate() -- this will ensure that clock
rates are recalculated and propagated correctly after those operations
are consolidated into clk_set_rate().

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>