clk: s2mps11: Use existing defines from bindings for clock IDs

The clock IDs must match between DeviceTree bindings and the driver.
There is already a header file used by DeviceTree sources so include it
in the driver to remove duplicated symbols.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>