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/corvus_defconfig b/configs/corvus_defconfig
index 6b89abf..cd0f993 100644
--- a/configs/corvus_defconfig
+++ b/configs/corvus_defconfig
@@ -40,6 +40,7 @@
 CONFIG_AT91_UTMI=y
 CONFIG_DFU_NAND=y
 # CONFIG_MMC is not set
+CONFIG_PHYLIB=y
 # CONFIG_SPL_DM_SERIAL is not set
 CONFIG_ATMEL_USART=y
 CONFIG_USB=y