samsung: exynos: Convert SROMC interface to a driver

Add a bus driver for this and use it to configure the bus parameters for
the Ethernet interface. Drop the old pre-driver-model code.

Switch over to use driver model for Ethernet.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 9de97cc..ff51a4e 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -661,6 +661,7 @@
 	select DM
 	select DM_GPIO
 	select DM_I2C
+	select DM_ETH
 	select DM_KEYBOARD
 	select DM_SERIAL
 	select DM_SPI