configs: Enable legacy SPI flash interface support

Enable legacy spi-flash interface support for boards which
supports qspi controller with connected spi-nor flash.

Signed-off-by: Jagan Teki <jteki@openedev.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Tested-by: Jagan Teki <jteki@openedev.com>
diff --git a/configs/zynq_zc702_defconfig b/configs/zynq_zc702_defconfig
index 0abb7a8..db2e92c 100644
--- a/configs/zynq_zc702_defconfig
+++ b/configs/zynq_zc702_defconfig
@@ -10,3 +10,4 @@
 # CONFIG_CMD_SETEXPR is not set
 CONFIG_OF_EMBED=y
 CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_SPI_FLASH=y