mips: sgi-ip22: Replace "s[n]?printf" with sysfs_emit in sysfs callbacks

Replace open-coded pieces with sysfs_emit() helper in sysfs .show()
callbacks.

Signed-off-by: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@gmail.com>
Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>