Add hm3301 driver from Seeed

From
https://github.com/Seeed-Studio/seeed-linux-dtoverlays/tree/master/modules/hm3301

Author: jadonk

drivers/iio/chemical/Kconfig

@@ -54,6 +54,14 @@ config CCS811
 	  Say Y here to build I2C interface support for the AMS
 	  CCS811 VOC (Volatile Organic Compounds) sensor
 
+config HM3301
+	tristate "HM3301 Particulate Matter sensor"
+	depends on I2C
+	select IIO_BUFFER
+	help
+	  Say Y here to build I2C interface support for the HM3301
+	  Particulate Matter laser interferometer sensor
+
 config IAQCORE
 	tristate "AMS iAQ-Core VOC sensors"
 	depends on I2C

drivers/iio/chemical/Makefile

@@ -9,6 +9,7 @@ obj-$(CONFIG_BME680) += bme680_core.o
 obj-$(CONFIG_BME680_I2C) += bme680_i2c.o
 obj-$(CONFIG_BME680_SPI) += bme680_spi.o
 obj-$(CONFIG_CCS811)		+= ccs811.o
+obj-$(CONFIG_HM3301)		+= hm3301.o
 obj-$(CONFIG_IAQCORE)		+= ams-iaq-core.o
 obj-$(CONFIG_PMS7003) += pms7003.o
 obj-$(CONFIG_SENSIRION_SGP30)	+= sgp30.o