Tegra20 AC97 driver doesn't manage the AC97 controller reset, relying on
implicit deassertion of the reset by tegra-clk driver, which needs to be
fixed since this behaviour is unacceptable by other Tegra drivers. Add
explicit reset control to the Tegra20 AC97 driver.

Note that AC97 reset was always specified in Tegra20 device-tree, hence
DTB ABI changes aren't required.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210314154459.15375-2-digetx@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>