env_onenand: change env_address type from unsigned long to loff_t

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: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: HeungJun, Kim <riverful.kim@samsung.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>