arm: socfpga: soc64: Define SMC function identifiers for PSCI SiP services

This header file defines the Secure Monitor Call (SMC) message
protocol for ATF (BL31) PSCI runtime services. It includes all
the PSCI SiP function identifiers for the secure runtime services
provided by ATF. The secure runtime services include System Manager's
registers access, 2nd phase bitstream FPGA reconfiguration, Remote
System Update (RSU) and etc.

Signed-off-by: Chee Hong Ang <chee.hong.ang@intel.com>
Signed-off-by: Siew Chin Lim <elly.siew.chin.lim@intel.com>