iio: dac: vf610: Drop dependency on OF

Nothing in this driver depends on OF firmware so drop the dependency
to remove the false impression such a dependency exists.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220413191611.46204-1-andriy.shevchenko@linux.intel.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/dac/Kconfig

@@ -442,7 +442,6 @@ config TI_DAC7612
 
 config VF610_DAC
 	tristate "Vybrid vf610 DAC driver"
-	depends on OF
 	depends on HAS_IOMEM
 	help
 	  Say yes here to support Vybrid board digital-to-analog converter.