arm: zynq: zybo: migrate CONFIG_DISPLAY to defconfig

Only add CONFIG_DISPLAY to defconfig because CONFIG_I2C_EDID
is automatically selected by CONFIG_DISPLAY

Signed-off-by: Luis Araneda <luaraneda@gmail.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/zynq_zybo_defconfig b/configs/zynq_zybo_defconfig
index 46a8f5a..8293171 100644
--- a/configs/zynq_zybo_defconfig
+++ b/configs/zynq_zybo_defconfig
@@ -72,3 +72,4 @@
 CONFIG_CI_UDC=y
 CONFIG_USB_GADGET_DOWNLOAD=y
 CONFIG_USB_FUNCTION_THOR=y
+CONFIG_DISPLAY=y