demmt: synchronous mode

It lets you decode mmt trace on the fly and feed decoded output
to mmiotrace (as markers), in synchronous manner.

See scripts/mmiotrace/mmt-app-demmt-mmiotrace.sh for usage example.
demmt: do not bother decoding method when it's not going to be printed
demmt: introduce mmt_printf
demmt: flush stdout after each line when in sync mode

Useful when stdout points to $debugfs/tracing/trace_marker.
demmt/nvrm: add NVRM_PARAM_SUBDEVICE_BUS_EXP_LNK_CAP
demmt/nvrm: IOCTL_UNK48 deals with PDISPLAY

In nv92 modesetting traces it touches registers from
PDISPLAY.VGA.* range.
demmt/nvrm: s/IOCTL_UNK41/IOCTL_SCHED_FIFO/

It pauses PFIFO, puts one channel on a playlist, resumes PFIFO,
pauses it again, puts all channels back on a playlist and resumes
PFIFO.

This ioctl is used only in modesetting traces.
demmt/nvrm: s/IOCTL_UNK4D/IOCTL_CONFIG/
demmt: print class info closer to created handles
demmt: s/SLI cond/SLI conditional/
demmt: add scripts