x86_64: don't need set default res if only have one root bus
x86_64: don't need set default res if only have one root bus

if there's only one root bus there's no need to split resources.

This patch fixes the issue described at:

  http://lkml.org/lkml/2008/4/10/304

Reported-and-bisected-by: Rafael J. Wysocki <a11f87183a953ab11f50fbafff689c5a7fa3506c@sisk.pl>
Tested-by: Rafael J. Wysocki <a11f87183a953ab11f50fbafff689c5a7fa3506c@sisk.pl>
Signed-off-by: Yinghai Lu <086d370ab7099a37fc1e7d4667336777772c5d99@gmail.com>
Signed-off-by: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>
Signed-off-by: Thomas Gleixner <00e4cf8f46a57000a44449bf9dd8cbbcc209fd2a@linutronix.de>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas