Current code has .enable_reg and .enable_mask settings, but the implementation
for corresponding callbacks are missing. Fix it.
Signed-off-by: Axel Lin <axel.lin@ingics.com> Tested-by: Robin Gong <b38343@freescale.com> Acked-by: Robin Gong <b38343@freescale.com> Signed-off-by: Mark Brown <broonie@linaro.org>