x86, efi: Mark disable_runtime as __initdata

disable_runtime is only referenced from __init functions, so mark it
as __initdata.

Reported-by: Yinghai Lu <yinghai@kernel.org>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1361545427-26393-1-git-send-email-matt@console-pimps.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>