Adds label for MI2S secondary block to allow follower projects to override
for the four speaker support which uses I2S SD1 line on gpio52 pin.
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Judy Hsiao <judyhsiao@chromium.org>
Link: https://lore.kernel.org/r/20210601022117.4071117-1-judyhsiao@chromium.orgSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>