perf doc: Add AMD IBS usage document

Add a perf man page document that describes how to exploit AMD IBS with
Linux perf. Brief intro about IBS and simple one-liner examples will help
naive users to get started. This is not meant to be an exhaustive IBS
guide. User should refer latest AMD64 Architecture Programmer's Manual
for detailed description of IBS.

Usage:

  $ man perf-amd-ibs

Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: ananth.narayan@amd.com
Cc: sandipan.das@amd.com
Cc: santosh.shukla@amd.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240620054104.815-1-ravi.bangoria@amd.com