drivers:iio:dac: Add AD3552R driver support

The AD3552R-16 is a low drift ultrafast, 16-bit accuracy,
current output digital-to-analog converter (DAC) designed
to generate multiple output voltage span ranges.
The AD3552R-16 operates with a fixed 2.5V reference.

Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ad3552r.pdf

Signed-off-by: Mihail Chindris <mihail.chindris@analog.com>
Link: https://lore.kernel.org/r/20211213110825.244347-3-mihail.chindris@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/dac/Kconfig

@@ -6,6 +6,16 @@
 
 menu "Digital to analog converters"
 
+config AD3552R
+	tristate "Analog Devices AD3552R DAC driver"
+	depends on SPI_MASTER
+	help
+	  Say yes here to build support for Analog Devices AD3552R
+	  Digital to Analog Converter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad3552r.
+
 config AD5064
 	tristate "Analog Devices AD5064 and similar multi-channel DAC driver"
 	depends on (SPI_MASTER && I2C!=m) || I2C

drivers/iio/dac/Makefile

@@ -4,6 +4,7 @@
 #
 
 # When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AD3552R) += ad3552r.o
 obj-$(CONFIG_AD5360) += ad5360.o
 obj-$(CONFIG_AD5380) += ad5380.o
 obj-$(CONFIG_AD5421) += ad5421.o