PM8916 has three TX inputs that each have an (optional) internal
RBIAS resistor. MIC BIAS Internal1/2 (for TX1/2) are already supported.
TX3 does not have its own MIC BIAS supply, instead it is also supplied
from MIC_BIAS1.

Now that we have simplified the MIC BIAS Internal* implementation
we can easily add support for it:

Add a MIC BIAS Internal3 supply that enables the internal RBIAS
resistor on TX3, and make sure to also enable the MIC_BIAS1 supply.

Tested-by: Nikita Travkin <nikitos.tr@gmail.com> # longcheer-l8150
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200114181229.42302-2-stephan@gerhold.netSigned-off-by: Mark Brown <broonie@kernel.org>