drm/xe/uapi: Rename xe perf layer as xe observation layer

drm/xe/uapi: Rename xe perf layer as xe observation layer

In Xe, the perf layer allows capture of HW counter streams. These HW
counters are generally performance related but don't have to be necessarily
so. Also, the name "perf" is a carryover from i915 and is not preferred.

Here we propose the name "observation" for this common layer which allows
capture of different types of these counter streams.

v2: Rename observability layer to observation layer (Lucas/Rodrigo)
v3: Rename sysctl file to "observation_paranoid" (Jose)

Fixes: 52c2e956dceb ("drm/xe/perf/uapi: "Perf" layer to support multiple perf counter stream types")
Fixes: fe8929bdf835 ("drm/xe/perf/uapi: Add perf_stream_paranoid sysctl")
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Acked-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240703164801.2561423-1-ashutosh.dixit@intel.com