[PATCH 6/9] tty: serial: pci: constify pci_device_id.

pci_device_id are not supposed to change at runtime. All functions working with pci_device_id provided by work with const pci_device_id. So mark the non-const structs as const. File size before: textdata bss dec hex filename 12626 18128 0 307547822

[PATCH 6/9] tty: serial: pci: constify pci_device_id.

pci_device_id are not supposed to change at runtime. All functions working with pci_device_id provided by work with const pci_device_id. So mark the non-const structs as const. File size before: textdata bss dec hex filename 12626 18128 0 307547822