83xx, kmeter: fix compile error

CONFIG_SYS_MALLOC_LEN is defined in the board config, and
the keymile-common.h, which collects common options used
by all keymile-boards. This results in a compile error
when compiling the kmeter1 board. So remove this define
in the board config file.
Signed-off-by: NHeiko Schocher <hs@denx.de>

include/configs/kmeter1.h

@@ -158,7 +158,6 @@
 #endif
 
 #define CONFIG_SYS_MONITOR_LEN		(384 * 1024) /* Reserve 384 kB for Mon */
-#define CONFIG_SYS_MALLOC_LEN		(128 * 1024) /* Reserved for malloc */
 
 /*
  * Initial RAM Base Address Setup