arm: socfpga: scan: Add code to get FPGA ID

Add code to get the FPGA type for Altera's SoCFPGA family of FPGA. The code
uses the scan manager to send jtag pulses that will return the FPGA ID.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>

arch/arm/mach-socfpga/include/mach/scan_manager.h

@@ -18,6 +18,7 @@ struct socfpga_scan_manager {
 };
 
 int scan_mgr_configure_iocsr(void);
+u32 scan_mgr_get_fpga_id(void);
 int iocsr_get_config_table(const unsigned int chain_id,
 			   const unsigned long **table,
 			   unsigned int *table_len);