- Give the timer, thermal, and error LVT entries an interrupt vector even

- Give the timer, thermal, and error LVT entries an interrupt vector even
  though these aren't used yet.
- Add missing function prototypes for some static functions.
- Allow lvt_mode() to handle an LVT entry with a delivery mode of fixed.
- Consolidate code duplicated in lapic_init() and lapic_setup() to program
  the spurious vector register of a local APIC in a static lapic_enable()
  function.
- Dump the timer, thermal, error, and performance counter LVT entries
  during lapic_dump().
- Program LVT pins (currently only LINT0 and LINT1) after the local
  APIC has been software enabled via lapic_enable() since otherwise the
  LVT programming will not be able to unmask LVT sources.