media: amphion: fix some error related with undefined reference to __divdi3

1. use ns_to_timespec64 instead of division method
2. use timespec64_to_ns instead of custom macro
3. remove unused custom macro
4. don't modify minus timestamp
5. remove some unused debug timestamp information

Signed-off-by: Ming Qian <ming.qian@nxp.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>