Rename SPL_ETH_SUPPORT to SPL_ETH

Rename this option so that CONFIG_IS_ENABLED can be used with it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/spl/spl_net.c b/common/spl/spl_net.c
index e140a63..d23b395 100644
--- a/common/spl/spl_net.c
+++ b/common/spl/spl_net.c
@@ -15,7 +15,7 @@
 #include <net.h>
 #include <linux/libfdt.h>
 
-#if defined(CONFIG_SPL_ETH_SUPPORT) || defined(CONFIG_SPL_USB_ETHER)
+#if defined(CONFIG_SPL_ETH) || defined(CONFIG_SPL_USB_ETHER)
 static ulong spl_net_load_read(struct spl_load_info *load, ulong sector,
 			       ulong count, void *buf)
 {
@@ -69,7 +69,7 @@
 }
 #endif
 
-#ifdef CONFIG_SPL_ETH_SUPPORT
+#ifdef CONFIG_SPL_ETH
 int spl_net_load_image_cpgmac(struct spl_image_info *spl_image,
 			      struct spl_boot_device *bootdev)
 {