TS-7970 U-boot changelog

Jun-17-2015	Added TS-7970 support
Jul-27-2015	Added fix for PCIe hang in Linux. Some of the GPR1 regs were not being reset after a reboot. U-boot will now reset these before going into Linux. This hang was not present on all CPUs, usually solo, and only if PCIe is enabled in the kernel.
Oct-07-2015	TS-7970 now has a POR on every reboot TS-7970 can reload the FPGA from a /boot/ts7970.vme file PUSH_SW is now read through i2c to free up FPGA_IRQ_1