sf: Add dual memories support - DUAL_PARALLEL

This patch added support for accessing dual memories in
parallel connection with single chipselect line from controller.

For more info - see doc/SPI/README.dual-flash

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
diff --git a/include/spi.h b/include/spi.h
index d214d82..ffd6647 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -47,6 +47,7 @@
 
 /* SPI bus connection options */
 #define SPI_CONN_DUAL_SHARED	1 << 0
+#define SPI_CONN_DUAL_SEPARATED	1 << 1
 
 /* Header byte that marks the start of the message */
 #define SPI_PREAMBLE_END_BYTE	0xec
@@ -66,7 +67,7 @@
  * @max_write_size:	If non-zero, the maximum number of bytes which can
  *			be written at once, excluding command bytes.
  * @memory_map:		Address of read-only SPI flash access.
- * @option:		Varies SPI bus options - separate bus.
+ * @option:		Varies SPI bus options - separate, shared bus.
  * @flags:		Indication of SPI flags.
  */
 struct spi_slave {