Fix some typos

This patch fixes three typos.
The first is a repetition of CONFIG_CMD_BSP.
The second makes the #endif comment match its #if.
The third is a spelling error.

Signed-off-by: Adrian Filipi <adrian.filipi@eurotech.com>
diff --git a/doc/README.nand-boot-ppc440 b/doc/README.nand-boot-ppc440
index a1c1d8c..1e9c102 100644
--- a/doc/README.nand-boot-ppc440
+++ b/doc/README.nand-boot-ppc440
@@ -9,7 +9,7 @@
 completely without NOR FLASH. This can be done by using the NAND
 boot feature of the 440 NAND flash controller (NDFC).
 
-Here a short desciption of the different boot stages:
+Here a short description of the different boot stages:
 
 a) IPL (Initial Program Loader, integrated inside CPU)
 ------------------------------------------------------