iio: bmc150: Add SPI driver

Add a simple SPI driver which initializes the spi regmap for the bmc150
core driver.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index bb00770..969428d 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -23,6 +23,7 @@
 	select IIO_TRIGGERED_BUFFER
 	select REGMAP
 	select BMC150_ACCEL_I2C if I2C
+	select BMC150_ACCEL_SPI if SPI
 	help
 	  Say yes here to build support for the following Bosch accelerometers:
 	  BMC150, BMI055, BMA250E, BMA222E, BMA255, BMA280.
@@ -35,6 +36,10 @@
 	tristate
 	select REGMAP_I2C
 
+config BMC150_ACCEL_SPI
+	tristate
+	select REGMAP_SPI
+
 config HID_SENSOR_ACCEL_3D
 	depends on HID_SENSOR_HUB
 	select IIO_BUFFER