Remove nox2apic kernel parameter

It turns out that this boot issue is an intersection of three issues:
1) Nvidia
2) X2APIC
3) VT-d
I had enabled #3 as part of setting up virtualbox. Simply disabling that
again makes the laptop boot just fine.

See:
https://fedoraproject.org/wiki/Common_F19_bugs#Boot_hangs_when_using_NVIDIA_discrete_graphics_on_some_Thinkpad_models_.28W520.2C_T420.29