linux-phytec-ti

regmap: Fix rbtreee build when not using debugfs

The debugfs functions don't stub themselves out quite so well as might
be desirable so provide functions which do do this stubbing.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>