MAINTAINERS: Update entries for IFS and SBL drivers

MAINTAINERS: Update entries for IFS and SBL drivers

Update the MAINTAINERS file to reflect the following changes for two Intel
platform drivers:

- Tony has agreed to take over maintainership of the Intel In-Field Scan
  (IFS) driver, and is now listed as the new maintainer.
- Remove myself as the maintainer for the Slim BootLoader (SBL) firmware
  update driver and mark it as Orphan. To the best of my knowledge, there
  is no one familiar with SBL who can take over this role.

These changes are being made as I will soon be leaving Intel.

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20250714164643.3879784-1-jithu.joseph@intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>