platform/x86: intel_telemetry: Remove unused telemetry_[gs]et_sampling_period()

platform/x86: intel_telemetry: Remove unused telemetry_[gs]et_sampling_period()

The functions:

  - telemetry_get_sampling_period()
  - telemetry_set_sampling_period()

were both added by the commit 378f956e3f93 ("platform/x86: Add Intel
Telemetry Core Driver") in 2016 but have remained unused.

They're each a tiny wrapper that is the only caller through a similarly
named function pointer, and for each function pointer there's a 'def'
empty implementation and a plt implementation.

Remove all of those components for each function.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://lore.kernel.org/r/20250608012512.377134-3-linux@treblig.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>