x86/local_apic: use newly added ARAT bit definition
x86/local_apic: use newly added ARAT bit definition

ARAT: APIC-Timer-always-running feature.

Suggested by:	mav
MFC after:	12 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase