pci_device_id are not supposed to change at runtime. All functions
working with pci_device_id provided by <linux/pci.h> work with
const pci_device_id. So mark the non-const structs as const.
File size before:
text data bss dec hex filename
14201 656 1760 16617 40e9 drivers/tty/moxa.o
File size After adding 'const':
text data bss dec hex filename
14329 528 1760 16617 40e9 drivers/tty/moxa.o