ARM: OMAP2+: Fix mismerge for timer.c between ff931c82 and da4a686a

Looks like the timer.c fixes in commit ff931c82 (ARM: OMAP: clocks:
Delay clk inits atleast until slab is initialized) got lost in a
merge with da4a686a

 (ARM: smp_twd: convert to use CLKSRC_OF init).

Without the omap_clk_init() calls none of OMAP family of devices
boot.

Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
[tony@atomide.com: updated comments to describe merge error]
Signed-off-by: Tony Lindgren <tony@atomide.com>