PCI: mobiveil: Allow mobiveil_host_init() to be used to re-init host

Allow the mobiveil_host_init() function to be used to re-init
host controller's PAB and GPEX CSR register block, since the NXP
integrated Mobiveil IP has to reset and then re-init the PAB
and GPEX CSR registers upon hot-reset.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
Reviewed-by: Andrew Murray <amurray@thegoodpenguin.co.uk>