katmai: fix section overlap problem

Since we didn't want to remove features from the configuration, we
decided to increase the U-Boot image size (add one flash sector).

Also changed the default environment definition to make it
independent of such changes.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Stefan Roese <sr@denx.de>
diff --git a/board/amcc/katmai/config.mk b/board/amcc/katmai/config.mk
index 115c1ae..c512b53 100644
--- a/board/amcc/katmai/config.mk
+++ b/board/amcc/katmai/config.mk
@@ -25,7 +25,7 @@
 # AMCC 440SPe Evaluation (Katmai) board
 #
 
-TEXT_BASE = 0xfffc0000
+TEXT_BASE = 0xFFFA0000
 
 PLATFORM_CPPFLAGS += -DCONFIG_440=1