ASoC: tegra: i2s: Fix typo/broken macro

Fix typo in macro TEGRA30_I2S_SLOT_CTRL_TOTAL_SLOTS_MASK.

Signed-off-by: Edward Cragg <edward.cragg@codethink.co.uk>
Signed-off-by: Jorge Sanjuan <jorge.sanjuan@codethink.co.uk>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>