4806 define x2apic feature flag
4807 pcplusmp & apix should use x2apic feature flag
Reviewed by: Robert Mustacchi <rm@joyent.com>

*** 20,29 ****
--- 20,32 ----
   */
  /*
   * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
+ /*
+  * Copyright 2014 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
+  */
  
  #include <sys/cpuvar.h>
  #include <sys/psm.h>
  #include <sys/archsystm.h>
  #include <sys/apic.h>
*** 92,102 ****
   * APIC register ops related data sturctures and functions.
   */
  void apic_send_EOI();
  void apic_send_directed_EOI(uint32_t irq);
  
- #define X2APIC_CPUID_BIT        21
  #define X2APIC_ENABLE_BIT       10
  
  /*
   * Local APIC Implementation
   */
--- 95,104 ----
*** 231,249 ****
  }
  
  int
  apic_detect_x2apic(void)
  {
-         struct cpuid_regs cp;
- 
          if (x2apic_enable == 0)
                  return (0);
  
!         cp.cp_eax = 1;
!         (void) __cpuid_insn(&cp);
! 
!         return ((cp.cp_ecx & (0x1 << X2APIC_CPUID_BIT)) ? 1 : 0);
  }
  
  void
  apic_enable_x2apic(void)
  {
--- 233,246 ----
  }
  
  int
  apic_detect_x2apic(void)
  {
          if (x2apic_enable == 0)
                  return (0);
  
!         return (is_x86_feature(x86_featureset, X86FSET_X2APIC));
  }
  
  void
  apic_enable_x2apic(void)
  {