iwlwifi: fix build for CONFIG_INPUT=n

iwlwifi: fix build for CONFIG_INPUT=n

Fix iwlwifi so that it builds cleanly with CONFIG_INPUT=n.
Also free the input device on exit.

drivers/built-in.o: In function `iwl_rfkill_unregister':
(.text+0xbf430): undefined reference to `input_unregister_device'
drivers/built-in.o: In function `iwl_rfkill_init':
(.text+0xbf51c): undefined reference to `input_allocate_device'
drivers/built-in.o: In function `iwl_rfkill_init':
(.text+0xbf5bf): undefined reference to `input_register_device'
drivers/built-in.o: In function `iwl_rfkill_init':
(.text+0xbf5e9): undefined reference to `input_free_device'
net/built-in.o: In function `rfkill_disconnect':
rfkill-input.c:(.text+0xe71e1): undefined reference to `input_close_device'
rfkill-input.c:(.text+0xe71e9): undefined reference to `input_unregister_handle'
net/built-in.o: In function `rfkill_connect':
rfkill-input.c:(.text+0xe723e): undefined reference to `input_register_handle'
rfkill-input.c:(.text+0xe724d): undefined reference to `input_open_device'
rfkill-input.c:(.text+0xe725c): undefined reference to `input_unregister_handle'
net/built-in.o: In function `rfkill_handler_init':
rfkill-input.c:(.init.text+0x36ec): undefined reference to `input_register_handler'
net/built-in.o: In function `rfkill_handler_exit':
rfkill-input.c:(.exit.text+0x112c): undefined reference to `input_unregister_handler'
make[1]: *** [.tmp_vmlinux1] Error 1

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>