arm: zynq: add support for the zybo z7 board

The board is manufactured by Digilent
Main features:
- Soc: XC7Z010 (Z7-10) or XC7Z020 (Z7-20)
- RAM: 1 GB DDR3L
- FLASH: 16 MB QSPI
- 1 Gbps Ethernet
- USB 2.0
- microSD slot
- Pcam camera connector
- HDMI Tx and Rx
- Audio codec: stereo out, stereo in, mic
- 5 (Z7-10) or 6 (Z7-20) Pmod ports
- 6 push-buttons, 4 switches, 5 LEDs
- 1 (Z7-10) or 2 (Z7-20) RGB LEDs

Signed-off-by: Luis Araneda <luaraneda@gmail.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/zynq_zybo_z7_defconfig b/configs/zynq_zybo_z7_defconfig
new file mode 100644
index 0000000..ad44e77
--- /dev/null
+++ b/configs/zynq_zybo_z7_defconfig
@@ -0,0 +1,68 @@
+CONFIG_ARM=y
+CONFIG_ARCH_ZYNQ=y
+CONFIG_SYS_TEXT_BASE=0x4000000
+CONFIG_SPL=y
+CONFIG_DEBUG_UART_BASE=0xe0001000
+CONFIG_DEBUG_UART_CLOCK=50000000
+CONFIG_SPL_STACK_R_ADDR=0x200000
+CONFIG_DEFAULT_DEVICE_TREE="zynq-zybo-z7"
+CONFIG_DEBUG_UART=y
+CONFIG_DISTRO_DEFAULTS=y
+CONFIG_FIT=y
+CONFIG_FIT_SIGNATURE=y
+CONFIG_FIT_VERBOSE=y
+CONFIG_IMAGE_FORMAT_LEGACY=y
+CONFIG_BOOTCOMMAND="run $modeboot || run distro_bootcmd"
+CONFIG_SPL_STACK_R=y
+CONFIG_SPL_OS_BOOT=y
+CONFIG_SPL_SPI_LOAD=y
+CONFIG_SYS_PROMPT="Zynq> "
+CONFIG_CMD_THOR_DOWNLOAD=y
+CONFIG_CMD_DFU=y
+# CONFIG_CMD_FLASH is not set
+CONFIG_CMD_FPGA_LOADBP=y
+CONFIG_CMD_FPGA_LOADFS=y
+CONFIG_CMD_FPGA_LOADMK=y
+CONFIG_CMD_FPGA_LOADP=y
+CONFIG_CMD_GPIO=y
+CONFIG_CMD_I2C=y
+CONFIG_CMD_MMC=y
+CONFIG_CMD_SF=y
+CONFIG_CMD_USB=y
+# CONFIG_CMD_SETEXPR is not set
+CONFIG_CMD_TFTPPUT=y
+CONFIG_CMD_CACHE=y
+CONFIG_CMD_EXT4_WRITE=y
+CONFIG_ENV_IS_IN_SPI_FLASH=y
+CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_SPL_DM_SEQ_ALIAS=y
+CONFIG_DFU_MMC=y
+CONFIG_DFU_RAM=y
+CONFIG_FPGA_XILINX=y
+CONFIG_FPGA_ZYNQPL=y
+CONFIG_DM_GPIO=y
+CONFIG_SYS_I2C_ZYNQ=y
+CONFIG_ZYNQ_I2C0=y
+CONFIG_ZYNQ_I2C1=y
+CONFIG_MMC_SDHCI=y
+CONFIG_MMC_SDHCI_ZYNQ=y
+CONFIG_SPI_FLASH=y
+CONFIG_SPI_FLASH_BAR=y
+CONFIG_SPI_FLASH_SPANSION=y
+CONFIG_PHY_REALTEK=y
+CONFIG_ZYNQ_GEM=y
+CONFIG_DEBUG_UART_ZYNQ=y
+CONFIG_ZYNQ_SERIAL=y
+CONFIG_ZYNQ_QSPI=y
+CONFIG_USB=y
+CONFIG_USB_EHCI_HCD=y
+CONFIG_USB_ULPI_VIEWPORT=y
+CONFIG_USB_ULPI=y
+CONFIG_USB_STORAGE=y
+CONFIG_USB_GADGET=y
+CONFIG_USB_GADGET_MANUFACTURER="Xilinx"
+CONFIG_USB_GADGET_VENDOR_NUM=0x03fd
+CONFIG_USB_GADGET_PRODUCT_NUM=0x0300
+CONFIG_CI_UDC=y
+CONFIG_USB_GADGET_DOWNLOAD=y
+CONFIG_USB_FUNCTION_THOR=y