arm: socfpga: Convert clock manager from struct to defines

arm: socfpga: Convert clock manager from struct to defines

Convert clock manager for Gen5, Arria 10 and Stratix 10 from struct
to defines.

Change to get clock manager base address from DT node instead of using
#define.

Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>