ASoC: soc.h: Add SOC_SINGLE_S_TLV() macro

Add a convenience macro for defining a single (mono) TLV control
with a signed value. This can already be done by using
SOC_DOUBLE_R_S_TLV() with the same address for left and right
registers, but a dedicated macro is more readable.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220405135419.1230088-2-rf@opensource.cirrus.com


Signed-off-by: Mark Brown <broonie@kernel.org>