regulator: add missing MODULE_DESCRIPTION() macro

On x86, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/regulator/da9121-regulator.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/regulator/max20411-regulator.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/regulator/rt4831-regulator.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/regulator/tps6286x-regulator.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240610-md-drivers-regulator-v2-1-cf39106d7e54@quicinc.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/da9121-regulator.c

@@ -1192,4 +1192,5 @@ static struct i2c_driver da9121_regulator_driver = {
 
 module_i2c_driver(da9121_regulator_driver);
 
+MODULE_DESCRIPTION("Dialog Semiconductor DA9121/DA9122/DA9220/DA9217/DA9130/DA9131/DA9132 regulator driver");
 MODULE_LICENSE("GPL v2");

drivers/regulator/max20411-regulator.c

@@ -161,4 +161,5 @@ static struct i2c_driver max20411_i2c_driver = {
 };
 module_i2c_driver(max20411_i2c_driver);
 
+MODULE_DESCRIPTION("Maxim MAX20411 High-Efficiency Single Step-Down Converter driver");
 MODULE_LICENSE("GPL");

drivers/regulator/rt4831-regulator.c

@@ -202,4 +202,5 @@ static struct platform_driver rt4831_regulator_driver = {
 module_platform_driver(rt4831_regulator_driver);
 
 MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
+MODULE_DESCRIPTION("Richtek RT4831 DSV Regulators driver");
 MODULE_LICENSE("GPL v2");

drivers/regulator/tps6286x-regulator.c

@@ -156,4 +156,5 @@ static struct i2c_driver tps6286x_regulator_driver = {
 
 module_i2c_driver(tps6286x_regulator_driver);
 
+MODULE_DESCRIPTION("TI TPS6286x Power Regulator driver");
 MODULE_LICENSE("GPL v2");