Migrate CONFIG_DRIVER_TI_CPSW to Kconfig

This converts CONFIG_DRIVER_TI_CPSW to Kconfig

Signed-off-by: Alex Kiernan <alex.kiernan@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/configs/am335x_sl50_defconfig b/configs/am335x_sl50_defconfig
index bf0efb3..ea70ef4 100644
--- a/configs/am335x_sl50_defconfig
+++ b/configs/am335x_sl50_defconfig
@@ -40,7 +40,7 @@
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_BOOTCOUNT_LIMIT=y
 CONFIG_MMC_OMAP_HS=y
-CONFIG_PHYLIB=y
+CONFIG_DRIVER_TI_CPSW=y
 CONFIG_SYS_NS16550=y
 CONFIG_OMAP3_SPI=y
 CONFIG_FAT_WRITE=y