ARM: uniphier: increase CONFIG_SYS_BOOTM_LEN to 32MB

The default value of CONFIG_SYS_BOOTM_LEN, 0x800000, causes error
when uncompressing Image.gz out of FIT image.

   Uncompressing Kernel Image ... Error: inflate() returned -5
Image too large: increase CONFIG_SYS_BOOTM_LEN
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

include/configs/uniphier.h

@@ -97,6 +97,7 @@
 
 #define CONFIG_LOADADDR			0x84000000
 #define CONFIG_SYS_LOAD_ADDR		CONFIG_LOADADDR
+#define CONFIG_SYS_BOOTM_LEN		(32 << 20)
 
 #define CONFIG_CMDLINE_EDITING		/* add command line history	*/