As observed on CFU1 board, without this delay we interrupt mask ROM
code execution even before it sets up any PLLs correctly preventing
Barebox from correctly starting up. Fixing this by adding PLL setup
code to OpenOCD script helps somewhat and Barebox starts, howerver CPU
started this way ends up being unstable crashing randomly during
further Barebox use.

Adding a simple 100 ms post reset delay resolves all of the described
issues. This is also consistent with how other ZII boards are set up.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>