Change max size of uncompressed uImage's to 8MByte and add
CFG_BOOTM_LEN to adjust this setting.

As mentioned by Robin Getz on 2005-05-24 the size of uncompressed
uImages was restricted to 4MBytes. This default size is now
increased to 8Mbytes and can be overrided by setting CFG_BOOTM_LEN
in the board config file.

Patch by Stefan Roese, 13 Mar 2006
diff --git a/README b/README
index c805437..b6cb981 100644
--- a/README
+++ b/README
@@ -421,7 +421,7 @@
 		Space should be pre-allocated in the dts for the bd_t.
 
 		CONFIG_OF_HAS_UBOOT_ENV
-		
+
 		The resulting flat device tree will have a copy of u-boot's
 		environment variables
 
@@ -1734,6 +1734,12 @@
 - CFG_MALLOC_LEN:
 		Size of DRAM reserved for malloc() use.
 
+- CFG_BOOTM_LEN:
+		Normally compressed uImages are limited to an
+		uncompressed size of 8 MBytes. If this is not enough,
+		you can define CFG_BOOTM_LEN in your board config file
+		to adjust this setting to your needs.
+
 - CFG_BOOTMAPSZ:
 		Maximum size of memory mapped by the startup code of
 		the Linux kernel; all data that must be processed by