dt-bindings: clock: Add S700 support for Actions Semi Soc's

Add clock bindings constants for action S700
Maintain common clock dt-bindings for Actions Semi SoC's
S700 and S900.

Signed-off-by: Parthiban Nallathambi <pn@denx.de>
Signed-off-by: Saravanan Sekar <sravanhome@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>