Add the clockid_name() function to get the clock name based on its
clockid. It will be used in the following changes.
Signed-off-by: Jiri Olsa
Cc: Alexander Shishkin
Cc: Andi Kleen
Cc: David Ahern
Cc: Geneviève Bastien
Cc: Ian Rogers
Cc: Jeremie Galarneau
Cc: Michael Petlan
Cc: Namhyung Kim
Cc: Peter Zijlstra
Cc: Wang Nan
Link: http://lore.kernel.org/lkml/20200805093444.314999-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo