arm: zynq: Enable FPGA/FPGA_XILINX via Kconfig

Enabling fpga via Kconfig.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/zynq_zc770_xm010_defconfig b/configs/zynq_zc770_xm010_defconfig
index a00919f..95e4a24 100644
--- a/configs/zynq_zc770_xm010_defconfig
+++ b/configs/zynq_zc770_xm010_defconfig
@@ -35,6 +35,7 @@
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_SPL_DM_SEQ_ALIAS=y
+CONFIG_FPGA_XILINX=y
 CONFIG_MMC_SDHCI=y
 CONFIG_MMC_SDHCI_ZYNQ=y
 CONFIG_SPI_FLASH=y