iio:cros_ec_sensors: Swap from a select to a depends in Kconfig

Would have merged this into the original patch as a fixup but I've already
pushed that out as an immutable branch for others to use so it'll have
to be a separate patch.  The original select had a typo as well.

Trying to do this via a select was opening a can of worms due to
a tree of other elements that would also have needed selecting.
A simple depends seems much mroe straight forward and appropriate in this
case.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>

drivers/iio/common/cros_ec_sensors/Kconfig

@@ -14,8 +14,7 @@ config IIO_CROS_EC_SENSORS_CORE
 
 config IIO_CROS_EC_SENSORS
 	tristate "ChromeOS EC Contiguous Sensors"
-	select IIO_CROS_EC_SENSORS_CORE
-	select MFD_CROSS_EC
+	depends on IIO_CROS_EC_SENSORS_CORE
 	help
 	  Module to handle 3d contiguous sensors like
 	  Accelerometers, Gyroscope and Magnetometer that are