MIPS: TXx9: 7 segment LED support

Add sysfs interface for 7 segment LED and implement access routine for
RBTX4939.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
5 files changed