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>
diff --git a/README b/README
index d362880..13cdac4 100644
--- a/README
+++ b/README
@@ -2554,6 +2554,15 @@
 
 		Enable support for fpga loadmk command
 
+		CONFIG_CMD_FPGA_LOADP
+
+		Enable support for fpga loadp command - load partial bitstream
+
+		CONFIG_CMD_FPGA_LOADBP
+
+		Enable support for fpga loadbp command - load partial bitstream
+		(Xilinx only)
+
 		CONFIG_SYS_FPGA_PROG_FEEDBACK
 
 		Enable printing of hash marks during FPGA configuration.