ide: qd65xx: Fix cast to pointer from integer of different size

Integer passed as pointer to drvdata should be cast to unsigned long to
avoid warning (compile testing on alpha architecture):

    drivers/ide/qd65xx.c: In function ‘qd6580_init_dev’:
    drivers/ide/qd65xx.c:312:27: warning:
        cast to pointer from integer of different size [-Wint-to-pointer-cast]

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>