ARM: ep93xx: Disable TS-72xx watchdog before uncompressing
The TS-72xx/73xx boards have a CPLD watchdog which is configured to
reset the board after 8 seconds, if the kernel is large enough that this
takes about this time to decompress the kernel, we will encounter a
spurious reboot.
Do not pull ts72xx.h, but instead locally define what we need to disable
the watchdog.