km-powerpc: move SYS_MALLOC_LEN out of keymile-common.h

It must be set to a different value for the later add kmp204x
architecture, because we are restricted to 1MB SRAM.

Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
diff --git a/include/configs/km/km-powerpc.h b/include/configs/km/km-powerpc.h
index 8ee0ac6..15fef24 100644
--- a/include/configs/km/km-powerpc.h
+++ b/include/configs/km/km-powerpc.h
@@ -32,6 +32,9 @@
 
 #define CONFIG_SYS_LOAD_ADDR	0x100000	/* default load address */
 
+/* Reserve 4 MB for malloc */
+#define CONFIG_SYS_MALLOC_LEN		(4 * 1024 * 1024)
+
 /******************************************************************************
  * (PRAM usage)
  * ... -------------------------------------------------------