fpga: Add support to load partial bitstreams

Added support to load partial bitstreams.
The partial bitstreams can be loaded using the below commands
Commands:
fpga loadp <dev> <addr> <size>
fpga loadbp <dev> <addr> <size>
The full bit streams can be loaded using the
old commands(fpga load and fpga loadb).

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

include/fpga.h

@@ -38,6 +38,7 @@ typedef struct {		/* typedef fpga_desc */
 
 typedef enum {
 	BIT_FULL = 0,
+	BIT_PARTIAL,
 } bitstream_type;
 
 /* root function definitions */