MAINTAINERS: Adjust vdso file entry in INTEL SGX

MAINTAINERS: Adjust vdso file entry in INTEL SGX

Commit

  693c819fedcd ("x86/entry/vdso: Refactor the vdso build")

moves the vdso sources into common, vdso32, and vdso64 subdirectories, but
misses to adjust the file entry in the INTEL SGX section of the MAINTAINERS
file.

Adjust the file entry in accordance with the file movement of the commit
above.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@redhat.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260119093835.114554-1-lukas.bulwahn@redhat.com