x86: Increase timeout for EHCI debug port reset completion in early printk

On one of my systems, several thousand iterations are needed before
CMD_RESET can be observed clear after setting it. Using a much
higher value here obviously cannot hurt.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
LKML-Reference: <4AA0E85D02000078000136F9@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>