Move PHYLIB to Kconfig

Signed-off-by: Alexandru Gagniuc <alex.g@adaptrum.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/configs/sbc8548_defconfig b/configs/sbc8548_defconfig
index 185825e..c31ee2e 100644
--- a/configs/sbc8548_defconfig
+++ b/configs/sbc8548_defconfig
@@ -16,6 +16,7 @@
 # CONFIG_CMD_IRQ is not set
 # CONFIG_MMC is not set
 CONFIG_MTD_NOR_FLASH=y
+CONFIG_PHYLIB=y
 # CONFIG_PCI is not set
 CONFIG_SYS_NS16550=y
 CONFIG_OF_LIBFDT=y