fpga: Add flag to indicate bitstream needs decompression

Add a flag that is passed to the write_init() callback, indicating
that the bitstream is compressed.

The low-level driver will deal with the flag, or return an error,
if compressed bitstreams are not supported.

Signed-off-by: Anatolij Gustschin <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Alan Tull <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

include/linux/fpga/fpga-mgr.h

···
  * FPGA_MGR_PARTIAL_RECONFIG: do partial reconfiguration if supported
  * FPGA_MGR_EXTERNAL_CONFIG: FPGA has been configured prior to Linux booting
  * FPGA_MGR_BITSTREAM_LSB_FIRST: SPI bitstream bit order is LSB first
+ * FPGA_MGR_COMPRESSED_BITSTREAM: FPGA bitstream is compressed
  */
 #define FPGA_MGR_PARTIAL_RECONFIG	BIT(0)
 #define FPGA_MGR_EXTERNAL_CONFIG	BIT(1)
 #define FPGA_MGR_ENCRYPTED_BITSTREAM	BIT(2)
 #define FPGA_MGR_BITSTREAM_LSB_FIRST	BIT(3)
+#define FPGA_MGR_COMPRESSED_BITSTREAM	BIT(4)
 
 /**
  * struct fpga_image_info - information specific to a FPGA image