Add the Zynq-based SYZYGY Hub board from Opal Kelly. The board
contains a Xilinx Zynq xc7z012s SoC, 1GB DDR3 RAM, and supports
booting from SD.
Signed-off-by: Tom McLeod <tom.mcleod@opalkelly.com>
Cc: Michal Simek <monstr@monstr.eu>
CC: Albert Aribaud <albert.u.boot@aribaud.net>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>