i.MX6: nitrogen6x: pedantic: BOOT_FROM==spi, not sd

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Acked-by: Stefano Babic <sbabic@denx.de>
diff --git a/board/boundary/nitrogen6x/nitrogen6s.cfg b/board/boundary/nitrogen6x/nitrogen6s.cfg
index 34fb9d0..ca30cd6 100644
--- a/board/boundary/nitrogen6x/nitrogen6s.cfg
+++ b/board/boundary/nitrogen6x/nitrogen6s.cfg
@@ -16,7 +16,7 @@
  * Boot Device : one of
  * spi, sd (the board has no nand neither onenand)
  */
-BOOT_FROM      sd
+BOOT_FROM      spi
 
 #define __ASSEMBLY__
 #include <config.h>