iio: frequency: adf4377: add missing select REMAP_SPI in Kconfig

This driver makes use of regmap_spi, but does not select the required
module.
Add the missing 'select REGMAP_SPI'.

Fixes: eda549e2 ("iio: frequency: adf4377: add support for ADF4377")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://patch.msgid.link/20241003-ad2s1210-select-v1-3-4019453f8c33@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/frequency/Kconfig

@@ -53,6 +53,7 @@ config ADF4371
 config ADF4377
 	tristate "Analog Devices ADF4377 Microwave Wideband Synthesizer"
 	depends on SPI && COMMON_CLK
+	select REGMAP_SPI
 	help
 	  Say yes here to build support for Analog Devices ADF4377 Microwave
 	  Wideband Synthesizer.