Move PHY_MICREL and PHY_MICREL_KSZ90X1 to Kconfig

Signed-off-by: Alexandru Gagniuc <alex.g@adaptrum.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/configs/vf610twr_defconfig b/configs/vf610twr_defconfig
index 031abbe..5f2fefd 100644
--- a/configs/vf610twr_defconfig
+++ b/configs/vf610twr_defconfig
@@ -28,5 +28,6 @@
 CONFIG_SYS_NAND_BUSWIDTH_16BIT=y
 CONFIG_SPI_FLASH=y
 CONFIG_PHYLIB=y
+CONFIG_PHY_MICREL=y
 CONFIG_DM_SERIAL=y
 CONFIG_FSL_LPUART=y