Increase allowable image size from 8MB to 32MB

CONFIG_SYS_BOOTM_LEN limits the size of the uncompressed kernel image to
8MB by default. Today, our image is 19MB in size when de-compressed.
This currently does not matter because lzmaBuffToBuffDecompress()
ignores this limit. However, this is going to change in a later commit.

Change-Id: Ia3bc0e58ed07afffbd72a9d0eeb70e1376e7ab4b
diff --git a/include/configs/ruby.h b/include/configs/ruby.h
index 1f049c4..acf90f0 100644
--- a/include/configs/ruby.h
+++ b/include/configs/ruby.h
@@ -115,6 +115,7 @@
 
 /* Default load address */
 #define CONFIG_SYS_LOAD_ADDR		RUBY_KERNEL_LOAD_DRAM_BEGIN	/* Default load address for bootm command */
+#define CONFIG_SYS_BOOTM_LEN		(32 * 1024 * 1024)
 
 /* Memory test */
 #define CONFIG_SYS_MEMTEST_START	CONFIG_ARC_FREE_BEGIN