ARM: OMAP2+: dmtimer: add device names to flck nodes

Add device name to OMAP2 dmtimer fclk nodes so that the fclk nodes can be
retrieved by doing a clk_get with the corresponding device pointers or
device names.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Tarun Kanti DebBarma <tarun.kanti@ti.com>
Signed-off-by: Thara Gopinath <thara@ti.com>
Acked-by: Cousson, Benoit <b-cousson@ti.com>
[tony@atomide.com: fixed typo in email address]
Signed-off-by: Tony Lindgren <tony@atomide.com>