zynq: add new target

Add support for Xilinx ZC702 Dev board

Zynq target is using 4.4 kernel and mainline 2016.1 u-boot.

Patch is tested with Xilinx ZC702 Dev board with SD boot mode.

known issues:
 - no QSPI driver in 4.4 kernel: no QSPI flash support
 - USB is not working in 4.4 kernel

Signed-off-by: Jason Wu <jason.wu.misc@gmail.com>

 create mode 100644 package/boot/uboot-zynq/Makefile
 create mode 100644 target/linux/zynq/Makefile
 create mode 100644 target/linux/zynq/base-files.mk
 create mode 100755 target/linux/zynq/base-files/etc/board.d/02_network
 create mode 100644 target/linux/zynq/base-files/etc/config/network
 create mode 100644 target/linux/zynq/base-files/etc/inittab
 create mode 100644 target/linux/zynq/config-4.4
 create mode 100644 target/linux/zynq/image/Makefile
 create mode 100755 target/linux/zynq/image/mkits.sh
 create mode 100644 target/linux/zynq/patches-4.4/0001-arm-dts-zynq-zc702.dts-Set-default-rdinit-to-sbin-in.patch
 create mode 100644 target/linux/zynq/profiles/zc702.mk

SVN-Revision: 48697