The current value means an mdelay(1) may execute up to 10000000 times,
which translates to around ~2.8 hours. This is probably not what the
orignal author had in mind. Let's instead use 10s, which is the same value
sh_mmcif is using for other timeouts.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>