perf vendor events: Update the JSON/events descriptions for power10 platform

perf vendor events: Update the JSON/events descriptions for power10 platform

Update the description for some of the JSON/events for power10 platform.

Fixes: 32daa5d7899e0343 ("perf vendor events: Initial JSON/events list for power10 platform")
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Disha Goel <disgoel@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230814112803.1508296-1-kjain@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>