drivers/built-in.o: In function `mantis_exit':
(.text+0x377413): undefined reference to `ir_input_unregister'
drivers/built-in.o: In function `mantis_input_init':
(.text+0x3774ff): undefined reference to `__ir_input_register'
If MANTIS_CORE is enabled but IR_CORE is not. Add the correct
dependency.