board/amcc/yucca/flash.c: Fix compile warning

Fix warning: flash.c:919: warning: dereferencing type-punned pointer
will break strict-aliasing rules

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Stefan Roese <sr@denx.de>
Acked-by: Stefan Roese <sr@denx.de>
diff --git a/board/amcc/yucca/flash.c b/board/amcc/yucca/flash.c
index eda49eb..d8c3b32 100644
--- a/board/amcc/yucca/flash.c
+++ b/board/amcc/yucca/flash.c
@@ -914,9 +914,10 @@
 
 static int write_word_2(flash_info_t * info, ulong dest, ulong data)
 {
-	volatile CONFIG_SYS_FLASH_WORD_SIZE *addr2 = (CONFIG_SYS_FLASH_WORD_SIZE *) (info->start[0]);
-	volatile CONFIG_SYS_FLASH_WORD_SIZE *dest2 = (CONFIG_SYS_FLASH_WORD_SIZE *) dest;
-	volatile CONFIG_SYS_FLASH_WORD_SIZE *data2 = (CONFIG_SYS_FLASH_WORD_SIZE *) & data;
+	ulong *data_ptr = &data;
+	volatile CONFIG_SYS_FLASH_WORD_SIZE *addr2 = (CONFIG_SYS_FLASH_WORD_SIZE *)(info->start[0]);
+	volatile CONFIG_SYS_FLASH_WORD_SIZE *dest2 = (CONFIG_SYS_FLASH_WORD_SIZE *)dest;
+	volatile CONFIG_SYS_FLASH_WORD_SIZE *data2 = (CONFIG_SYS_FLASH_WORD_SIZE *)data_ptr;
 	ulong start;
 	int i;