Otherwise with INPUT=m, EEEPC_LAPTOP=y one gets

drivers/built-in.o: In function `input_sync':
eeepc-laptop.c:(.text+0x18ce51): undefined reference to `input_event'
drivers/built-in.o: In function `input_report_key':
eeepc-laptop.c:(.text+0x18ce73): undefined reference to `input_event'
drivers/built-in.o: In function `eeepc_hotk_check':
eeepc-laptop.c:(.text+0x18d05f): undefined reference to `input_allocate_device'
eeepc-laptop.c:(.text+0x18d10f): undefined reference to `input_register_device'
eeepc-laptop.c:(.text+0x18d131): undefined reference to `input_free_device'
drivers/built-in.o: In function `eeepc_backlight_exit':
eeepc-laptop.c:(.text+0x18d546): undefined reference to `input_unregister_device'

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>