kconfig: zynq: Add ZYBO board

Add a defconfig and Kconfigury for the Digilent ZYBO board.

Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Acked-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/cpu/armv7/zynq/Kconfig b/arch/arm/cpu/armv7/zynq/Kconfig
index f418cd6..3a52535 100644
--- a/arch/arm/cpu/armv7/zynq/Kconfig
+++ b/arch/arm/cpu/armv7/zynq/Kconfig
@@ -15,6 +15,9 @@
 config TARGET_ZYNQ_ZC770
 	bool "Zynq ZC770 Board"
 
+config TARGET_ZYNQ_ZYBO
+	bool "Zynq Zybo Board"
+
 endchoice
 
 config SYS_BOARD
@@ -31,5 +34,6 @@
 	default "zynq_microzed" if TARGET_ZYNQ_MICROZED
 	default "zynq_zc70x" if TARGET_ZYNQ_ZC70X
 	default "zynq_zc770" if TARGET_ZYNQ_ZC770
+	default "zynq_zybo" if TARGET_ZYNQ_ZYBO
 
 endif
diff --git a/configs/zynq_zybo_defconfig b/configs/zynq_zybo_defconfig
new file mode 100644
index 0000000..a00f4fc
--- /dev/null
+++ b/configs/zynq_zybo_defconfig
@@ -0,0 +1,4 @@
+CONFIG_SPL=y
++S:CONFIG_ARM=y
++S:CONFIG_ZYNQ=y
++S:CONFIG_TARGET_ZYNQ_ZYBO=y