linux-imx

microblaze: Remove architecture heart beat code

There is no reason to keep this gpio based code in architecture. Use
ledtrig-heartbeat.c instead which is much more flexible then this
ancient code.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>