sf: Add bank addr code in CONFIG_SPI_FLASH_BAR

Defined bank addr code on CONFIG_SPI_FLASH_BAR macro, to reduce the
size for existing boards which has < 16Mbytes SPI flashes.

It's upto user which has provision to use the bank addr code for
flashes which has > 16Mbytes.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/README b/README
index cd0336c..6db33c4 100644
--- a/README
+++ b/README
@@ -2509,6 +2509,11 @@
 		Define this option to include a destructive SPI flash
 		test ('sf test').
 
+		CONFIG_SPI_FLASH_BAR		Ban/Extended Addr Reg
+
+		Define this option to use the Bank addr/Extended addr
+		support on SPI flashes which has size > 16Mbytes.
+
 - SystemACE Support:
 		CONFIG_SYSTEMACE