arm: socfpga: Convert system manager from struct to defines

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

Change to get system 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>
diff --git a/arch/arm/mach-socfpga/include/mach/system_manager.h b/arch/arm/mach-socfpga/include/mach/system_manager.h
index 7e76df7..7f05029 100644
--- a/arch/arm/mach-socfpga/include/mach/system_manager.h
+++ b/arch/arm/mach-socfpga/include/mach/system_manager.h
@@ -6,6 +6,8 @@
 #ifndef _SYSTEM_MANAGER_H_
 #define _SYSTEM_MANAGER_H_
 
+phys_addr_t socfpga_get_sysmgr_addr(void);
+
 #if defined(CONFIG_TARGET_SOCFPGA_STRATIX10)
 #include <asm/arch/system_manager_s10.h>
 #else