env_onenand: change env_address type from unsigned long to loff_t

If use the onenand boot, the env_relocate_spec() calls mtd->read(),
and the type of the argument #2 of mtd->read() was changed to loff_t.
But, the "env_addr" type is still unsigned long, thus this patch change
the type from unsigned long to loff_t.
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NHeungJun, Kim <riverful.kim@samsung.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

common/env_onenand.c

@@ -58,7 +58,7 @@ uchar env_get_char_spec(int index)
 
 void env_relocate_spec(void)
 {
-	unsigned long env_addr;
+	loff_t env_addr;
 	int use_default = 0;
 	size_t retlen;