remove timecode subframe configuration

There is no actual use-case to set it to anything else than 100.
timecode subframes are only used for ruler marks and the snap to grid.
libtimecode is still /aware/ of the subframe setting.

git-svn-id: svn://localhost/ardour2/branches/3.0@13817 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/ardour/ltc_slave.cc

@@ -95,7 +95,6 @@ void
 LTC_Slave::parameter_changed (std::string const & p)
 {
 	if (p == "slave-timecode-offset"
-			|| p == "subframes-per-frame"
 			|| p == "timecode-format"
 			) {
 		parse_timecode_offset();

libs/ardour/mtc_slave.cc

@@ -118,7 +118,6 @@ void
 MTC_Slave::parameter_changed (std::string const & p)
 {
 	if (p == "slave-timecode-offset"
-			|| p == "subframes-per-frame"
 			|| p == "timecode-format"
 			) {
 		parse_timecode_offset();