docs/sp_SP: Add translation of process/maintainer-kvm-x86.rst

Translate Documentation/process/maintainer-kvm-x86.rst into Spanish.

Co-developed-by: Juan Embid <jembid@ucm.es>
Signed-off-by: Juan Embid <jembid@ucm.es>
Signed-off-by: Carlos Bilbao <carlos.bilbao.osdev@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
[jc: fixed apply- and build-time warnings]
Link: https://lore.kernel.org/r/20240626221942.2780668-1-carlos.bilbao.osdev@gmail.com