PCI: mobiveil: Initialize Primary/Secondary/Subordinate bus numbers

The reset value of Primary, Secondary and Subordinate bus numbers is
zero which is a broken setup.

Program a sensible default value for Primary/Secondary/Subordinate
bus numbers.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Minghuan Lian <Minghuan.Lian@nxp.com>
Reviewed-by: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>