[LMB]: Make lmb support large physical addressing

Convert the lmb code to use u64 instead of unsigned long for physical
addresses and sizes.  This is needed to support large amounts of RAM
on 32-bit systems that support 36-bit physical addressing.

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>