spi : convert altera_spi to driver model

Convert altera_spi to driver model

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Reviewed-by: Jagan Teki <jteki@openedev.com>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 8e04fce..2f8cf19 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -15,6 +15,14 @@
 
 if DM_SPI
 
+config ALTERA_SPI
+	bool "Altera SPI driver"
+	help
+	  Enable the Altera SPI driver. This driver can be used to
+	  access the SPI NOR flash on platforms embedding this Altera
+	  IP core. Please find details on the "Embedded Peripherals IP
+	  User Guide" of Altera.
+
 config CADENCE_QSPI
 	bool "Cadence QSPI driver"
 	help