clk: socfpga: Remove socfpga_init_clocks

The only thing that socfpga_init_clocks was doing is setting up the smp_twd clk.
Now that twd-timer's clock phandle is populated in the DTS, we can remove
this function.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>