perf tools: Add a place to put kernel config fragments for test runs

Defconfig doesn't give full coverage for a perf test run, so these can
be merged with defconfig to do so. It's not complete yet, but is a
starting point as a place to add to when a specific test needs something
extra to run.

Signed-off-by: James Clark <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: [e-mail]
Cc: Alexander Shishkin <[e-mail]>
Cc: Ian Rogers <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Leo Yan <[e-mail]>
Cc: Mark Brown <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Masahiro Yamada <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/tests/config-fragments/README

···
+This folder is for kernel config fragments that can be merged with
+defconfig to give full test coverage of a perf test run. This is only
+an optimistic set as some features require hardware support in order to
+pass and not skip.
+
+'config' is shared across all platforms, and for arch specific files,
+the file name should match that used in the ARCH=... make option.

tools/perf/tests/config-fragments/arm64

···
+CONFIG_CORESIGHT_SOURCE_ETM4X=y

tools/perf/tests/config-fragments/config

···
+CONFIG_TRACEPOINTS=y
+CONFIG_STACKTRACE=y
+CONFIG_NOP_TRACER=y
+CONFIG_RING_BUFFER=y
+CONFIG_EVENT_TRACING=y
+CONFIG_CONTEXT_SWITCH_TRACER=y
+CONFIG_TRACING=y
+CONFIG_GENERIC_TRACER=y
+CONFIG_FTRACE=y
+CONFIG_FTRACE_SYSCALLS=y
+CONFIG_BRANCH_PROFILE_NONE=y