nand: fix address overflow

The shifts of the address mask and value shift beyond 32 bits when there
are 5 address cycles.

Cc: qemu-stable@nongnu.org
Signed-off-by: Rabin Vincent <rabin.vincent@axis.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
