Staging: w35und: use msleep() and udelay()

This patch removes the OS_SLEEP() wrapper and changes the call-sites to use
msleep() and udelay() where appropriate.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>