ARM: S5P6440: Add clocks of type 'struct clksrc_clk'.

This patch adds the following.

1. Add new definitions of clock of type 'struct clksrc_clk'.
2. Add gate control function for GATE_SCLK1 which is required
   for new clock additions.

Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>