dw_pcie_host_init() calls the dw_pcie_ops.host_init() callback to do
platform-specific host initialization.

Add a dw_pcie_ops.host_deinit() callback to perform the corresponding
cleanups in dw_pcie_host_deinit() and in dw_pcie_host_init() failure paths.

Link: https://lore.kernel.org/r/20220624143947.8991-9-Sergey.Semin@baikalelectronics.ruSigned-off-by: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>