Made await_ide(), which polls for an ide status change, check the status

Made await_ide(), which polls for an ide status change, check the status
reg much more often. In my case this reduced the time spent in coreboot
by 1.5 sec!
The timeout values of course aren't changed, only the granularity. Also,
I didn't see any udelay() implementation that looked like it couldn't
cope with 10 us delays. (Most are written as for (...) inb(0x80) loops.)

Signed-off-by: Jens Rottmann <JRottmann@LiPPERTEmbedded.de>
Acked-by: Marc Jones <marc.jones@amd.com>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3690 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1