[ARM] Anubis: Fix sparse warnings for items that should be static

Make 'anubis_ide_platdata' statis as it is not used outside
the file it is in, fixing the following sparse warning:

mach-anubis.c:246:27: warning: symbol 'anubis_ide_platdata' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>