arm: socfpga: stratix10: Add generic FPGA reconfig mailbox API for S10

Add a generic mailbox API for FPGA reconfig status which can be
called by others. This new function accepts 2 different mailbox
commands: CONFIG_STATUS or RECONFIG_STATUS.

Signed-off-by: Ang, Chee Hong <chee.hong.ang@intel.com>
2 files changed