net: gem: Move gem to Kconfig

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>
diff --git a/configs/xilinx_zynqmp_ep_defconfig b/configs/xilinx_zynqmp_ep_defconfig
index 79304c1..22915f1 100644
--- a/configs/xilinx_zynqmp_ep_defconfig
+++ b/configs/xilinx_zynqmp_ep_defconfig
@@ -22,4 +22,5 @@
 CONFIG_CMD_TIMER=y
 CONFIG_OF_EMBED=y
 CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_ZYNQ_GEM=y
 # CONFIG_REGEX is not set