This patch adds at91 smd (Soft Modem) clock implementation using common clk
framework.

Not used by any driver right now.
Signed-off-by: NBoris BREZILLON <b.brezillon@overkiz.com>
Acked-by: NMike Turquette <mturquette@linaro.org>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>