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/sbc8641d_defconfig b/configs/sbc8641d_defconfig
index 200500f..7174e00 100644
--- a/configs/sbc8641d_defconfig
+++ b/configs/sbc8641d_defconfig
@@ -12,5 +12,6 @@
 CONFIG_DOS_PARTITION=y
 # CONFIG_MMC is not set
 CONFIG_MTD_NOR_FLASH=y
+CONFIG_PHYLIB=y
 CONFIG_SYS_NS16550=y
 CONFIG_OF_LIBFDT=y