ARM: zynq: Move FLASH_BAR to Kconfig

Clean up config and use Kconfig more.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/zynq_zc770_xm013_defconfig b/configs/zynq_zc770_xm013_defconfig
index cfec336..9672940 100644
--- a/configs/zynq_zc770_xm013_defconfig
+++ b/configs/zynq_zc770_xm013_defconfig
@@ -15,4 +15,5 @@
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_SPL_DM_SEQ_ALIAS=y
 CONFIG_SPI_FLASH=y
+CONFIG_SPI_FLASH_BAR=y
 CONFIG_ZYNQ_GEM=y