coresight: tmc: Add support for reading crash data

* Add support for reading crashdata using special device files.
  The special device files /dev/crash_tmc_xxx would be available
  for read file operation only when the crash data is valid.

* User can read the crash data as below

  For example, for reading crash data from tmc_etf sink

  #dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin

Signed-off-by: Anil Kumar Reddy <areddy3@marvell.com>
Signed-off-by: Tanmay Jagdale <tanmay@marvell.com>
Signed-off-by: Linu Cherian <lcherian@marvell.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250212114918.548431-6-lcherian@marvell.com