General Parallel Audio (GPA) interface is one of the supported
audio interface for synopsys HDMI module, which has verified for
i.MX8MPlus platform.
This is initial version for GPA.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/f21ba3e8c4d9d028ac74c6f3c588ddbffe739399.1649989179.git.Sandor.yu@nxp.com