MAINTAINERS: Update the file list in the TDX entry.

MAINTAINERS: Update the file list in the TDX entry.

This includes files that were previously missed in the TDX entry file
list and makes it more future-proof. Most importantly, this now covers
the recently added KVM enabling.

[ dhansen: move from explicit files to "tdx" filename match ]

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20250708101922.50560-2-kirill.shutemov%40linux.intel.com