ASoC: tegra30: ahub: Reset global variable

Tegra30 AHUB uses global variable that is never reset by the driver on
a probe failure and on driver removal, meaning that driver will never try
to re-probe and can't be unbound. Make driver to reset the variable.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210314154459.15375-16-digetx@gmail.com


Signed-off-by: Mark Brown <broonie@kernel.org>