perf docs: Fix man page build wrt perf-arm-coresight.txt

perf build assumes documentation files starting with "perf-" are man
pages but perf-arm-coresight.txt is not a man page:

  asciidoc: ERROR: perf-arm-coresight.txt: line 2: malformed manpage title
  asciidoc: ERROR: perf-arm-coresight.txt: line 3: name section expected
  asciidoc: FAILED: perf-arm-coresight.txt: line 3: section title expected
  make[3]: *** [Makefile:266: perf-arm-coresight.xml] Error 1
  make[3]: *** Waiting for unfinished jobs....
  make[2]: *** [Makefile.perf:895: man] Error 2

Fix by renaming it.

Fixes: dc2e0fb ("perf test coresight: Add relevant documentation about ARM64 CoreSight testing")
Reported-by: Christian Borntraeger <[email protected]>
Reported-by: Sven Schnelle <[email protected]>
Reviewed-by: Leo Yan <[email protected]>
Signed-off-by: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Carsten Haitzler <[email protected]>
Cc: [email protected]
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Poirier <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: ahunter6