Pwm_out_rc_in Quesition. ( snap dragon flight )

I would really appreciate it if you could guide me.

I insert line( drivers/pwm_out_rc_in ) at posix_eagle_legacy_driver_default.cmake file.
And I build eagle platform by use command (‘make eagle_legacy_default’).

posix_eagle_legacy_driver_default.cmake

drivers/qshell/posix
drivers/pwm_out_rc_in ← insert line

But there is happended build erro like below

/home/abu/eagle/Fimrwar_Origin3/Firmware/src/drivers/pwm_out_rc_in/pwm_out_rc_in.cpp:53:31:
fatal error: dev_fs_lib_serial.h: No such file or directory #include <dev_fs_lib_serial.h>

I can search the file ( dev_fs_lib_serial.h ) at Firmware/src/lib/DriverFramework/dspal/include directory.
Please guide me where point do I modified file to remove this build erro.