ppc4xx: amcc: Set CONFIG_SYS_BOOTMAPSZ to 16MB for big kernels

This patch changes CONFIG_SYS_BOOTMAPSZ from 8MB to 16MB which is the
initial TLB on 40x PPC's in the Linux kernel. With this change even bigger
Linux kernels (> 8MB) can be booted.

This patch also sets CONFIG_SYS_BOOTM_LEN to 16MB (default 8MB) to enable
decompression of bigger images.

Signed-off-by: Stefan Roese <sr@denx.de>

include/configs/amcc-common.h

@@ -137,10 +137,11 @@
 
 /*
  * For booting Linux, the board info and command line data
- * have to be in the first 8 MB of memory, since this is
- * the maximum mapped by the Linux kernel during initialization.
+ * have to be in the first 16 MB of memory, since this is
+ * the maximum mapped by the 40x Linux kernel during initialization.
  */
-#define CONFIG_SYS_BOOTMAPSZ		(8 << 20) /* Initial Memory map for Linux */
+#define CONFIG_SYS_BOOTMAPSZ		(16 << 20) /* Initial Memory map for Linux */
+#define CONFIG_SYS_BOOTM_LEN		(16 << 20) /* Increase max gunzip size */
 
 /*
  * Internal Definitions