MAINTAINERS: intel_telemetry: Update maintainers info

Remove Souvik who has left this role. Add Rajneesh and David who work
jointly on telemetry updates for new platforms.

Signed-off-by: David E. Box <david.e.box@intel.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>