ARM: OMAP: duplicate plat-omap/clock.c into mach-omap[12]/clock.c

Duplicate arch/arm/plat-omap/clock.c into arch/arm/mach-omap1/clock.c
and arch/arm/mach-omap2/clock.c.  This is to support people who are working
on the ARM single image kernel and the OMAP common clock framework
conversion.

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