MAINTAINERS: add reviewer for Spanish translations

Add Avadhut Naik as reviewer of the Spanish translations of the
documentation.

Signed-off-by: Carlos Bilbao <carlos.bilbao@amd.com>
Acked-by: Avadhut Naik <avadhut.naik@amd.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20231218154308.3314929-1-carlos.bilbao@amd.com

Author: Zildj1an

MAINTAINERS

@@ -20360,6 +20360,7 @@ F:	drivers/media/dvb-frontends/sp2*
 
 SPANISH DOCUMENTATION
 M:	Carlos Bilbao <carlos.bilbao@amd.com>
+R:	Avadhut Naik <avadhut.naik@amd.com>
 S:	Maintained
 F:	Documentation/translations/sp_SP/