ARM: OMAP2+: PM: share clkdms_setup() across OMAP2, 3, 4

clkdms_setup() is identical across OMAP2, 3, and 4, so share it.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>