Fix a typo that accidentally sets "val" to zero when we intended just to
clear BIT(0).

Fixes: 90d52d57 ("PCI: qcom: Add support for IPQ4019 PCIe controller")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: NStanimir Varbanov <svarbanov@mm-sol.com>
Acked-by: NJohn Crispin <john@phrozen.org>