ext4: Add new ext4 trim tracepoints

Add ext4_trim_extent and ext4_trim_all_free.

Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Blechd0se <alex.christ@hotmail.de>

Conflicts:
	include/trace/events/ext4.h