perf: enable coresight if enabled in MACHINE_FEATURES

perf: enable coresight if enabled in MACHINE_FEATURES

Enable the CoreSight[1] functionality in perf[2] if 'coresight' is in the
MACHINE_FEATURES.

Note that enabling this will mean a dependency on the opencsd recipe,
which is currently part of meta-arm[3]. I don't think this is a problem
as this recipe is Arm-specific, and as this is a new feature the
behaviour is opt-in so shouldn't break any existing machines.

[1] https://docs.kernel.org/trace/coresight/coresight.html
[2] https://docs.kernel.org/trace/coresight/coresight-perf.html
[3] https://git.yoctoproject.org/meta-arm/tree/meta-arm/recipes-devtools/opencsd

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>