platform/x86/intel/pmt/telemetry: Move overlap check to post-decode hook

platform/x86/intel/pmt/telemetry: Move overlap check to post-decode hook

Update the telemetry namespace to use the new PMT class pre/post decode
interface. The overlap check, which previously occurred during header
decode, is now performed in the post-decode hook once header fields are
populated. This preserves existing behavior while reusing the same header
decode logic across PMT drivers.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/2f5e429a38e22eb45fcfaaca4e037fa395d4f199.1781294741.git.david.e.box@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>